Ying-Dong Liu
email: yingdong.liu@etu.unistra.fr

Bertrand Marne
email: bertrand.marne@univ-lemans.fr

Iza Marfisi- Schottman

Tiphaine Galpin
email: tiphaine.galpin@univ-lemans.fr

Aurore Caruso
email: aurore.caruso@univ-lemans.fr

EscapeCell: Serious Game Integration to a University Biology Course on an E-learning Platform

Keywords: Serious Games, cellular biology, university, e-learning platform, gamification

This paper presents EscapeCell, a Serious Game to help undergraduate students understand plant cellular biology. Each chapter is matched with one mini-game., a gamification module integrated into the e-learning platform and several reminders of the game in the course material. We conducted a study on 117 students to compare their exam results with a control group from last year. We also correlated the collected feedback from the students and usage tracks. This helped us measure the usefulness of specific game elements, such as a nonplayer character that provides help and bonus information modules hidden throughout the mini-games. The preliminary results indicate that the integration of EscapeCell improves students' learning outcomes in the final exam and that Blob, the virtual tutor, facilitates the usage of mini-games. Although the bonus information modules do not directly correlate with the final exam result, but they show a positive correlation with the scores of the intermediate tests -the multiplechoice questions (MCQs) -taken by the students just after playing the minigames.

1

Introduction

The context of this paper is a plant cell biology course, part of the undergraduate curriculum of first-year students (approx. 120) at the Biology Faculty. The teacher in charge of this course noticed that its content was often challenging for students. They have difficulties grasping concepts, vocabulary, and phenomena, and staying motivated. Gamification and Serious Games (SGs) have proven to be efficient tools to engage students and favour learning [START_REF] Malone | Making learning fun: A taxonomy of intrinsic motivations for learning. Making Learning Fun: A Taxonomy of Intrinsic Motivations for Learning[END_REF][START_REF] Gee | What Video Games Have to Teach Us About Learning and Literacy[END_REF]. Hence, we present an attempt to overcome these challenges by using both dedicated serious mini-games and a specific gamification module for the e-learning platform used by students. Together, they form a whole called EscapeCell.

EscapeCell's design and usage are the opportunity for a study that aims to address two key research questions. On the one hand, does the use of SGs improve students' Liu, YD., Marne, B., Marfisi-Schottman, I., Galpin, T., Caruso, A. (2023). EscapeCell: Serious Game Integration to a University Biology Course on an E-Learning Platform. In Proceedings of the Games and Learning Alliance Conference (GALA). Lecture Notes in Computer Science, vol 14475. Springer, Cham. Bublin, Ireland, 29 November to 1st December 2023, pp 13-22. learning outcomes? This question aims to understand if EscapeCell is effective in this learning context. On the other hand, the game designers of EscapeCell added two special game elements to the mini-games: A non-player character, called "Blob", and bonus information modules. Our second research question is about understanding the influence of Blob and the bonus information modules on the student's game experience. To this end, Section 2 begins with a brief review of SGs and gamification in higher education and biology courses. Section 3 elaborates on the context surrounding the creation of EscapeCell, along with some game design elements. The experiment and data collection method will be described in Section 4. The results gathered will be presented and discussed in Section 5. Finally, Section 6 will conclude our research.

2

State of the Art and Scientific Positioning

Literature shows many examples of SGs about biology and cell biology for secondary school. Kara and Cheng propose systematic reviews that show that most of them are adventure games, simulations or sport-type games [START_REF] Kara | A systematic review of the use of serious games in science education[END_REF][START_REF] Cheng | The use of serious games in science education: a review of selected empirical research from 2002 to 2013[END_REF]. Authors also share the need for a strong integration of the SGs in the courses and the learning environment, as suggested by the biology teacher working with us. Nonetheless, there are few publications about SGs in (cell) biology for higher education, and the studies are not thorough enough to explore learning outcomes [START_REF] Schneller | Meta! Blast computer game: a pipeline from science to 3D art to education[END_REF][START_REF] Wurtele | Meta! Blast: a serious game to explore the complexities of structural and metabolic cell biology[END_REF].

Recent work on biology also confirms main findings of the prior state of the art [START_REF] Hodges | Pedagogy, partnership, and collaboration: a longitudinal, empirical study of serious educational gameplay in secondary biology classrooms[END_REF]: SGs must help explore things that teachers cannot provide, teachers should accompany the learners during the play, SGs must be very interactive and their design must include the teachers.

Following our cell biology teacher needs and Kara's findings [START_REF] Kara | A systematic review of the use of serious games in science education[END_REF] about the importance of SGs' integration to courses, we also explored results about e -learning platform gamification. Recent systematic research shows few articles have addressed motivation and gamification in higher education [START_REF] Khaldi | Gamification of e-learning in higher education: a systematic literature review[END_REF]. However, there is recent research by Reyssier et al. [START_REF] Reyssier | The Impact of Game Elements on Learner Motivation: Influence of Initial Motivation and Player Profile[END_REF] that shows that gamification is (more) suitable to our target, which is the less motivated learners. The most efficient approach to a gamification would be one that is specifically tailored to the learner. Nevertheless, as detailed in section 3, we cannot alter every aspect of the course and design a fully adaptable SG. Therefore, we focused on the findings from Reyssier et al. that can be generalized to most of our targeted learners: avatars, badges, and progress bars are harmless gamification mechanics for most player types and can be used safely to enhance motivation.

As we wanted to go further to engage learners, we also wanted to explore bonuses and secondary objective mechanics. Indeed, in a wide study (n = 27000), Andersen et al. show that secondary objectives that support the primary goal of the game are consistently useful and very positive on the learning outcomes and motivation [START_REF] Andersen | On the harmfulness of secondary game objectives[END_REF].

3

Serious Game EscapeCell

Objectives and Challenges of the Cell Biology Course

During the cell biology course, the lecturer introduces a large number of new terminology and complex phenomena that are not easy to grasp such as operation photosynthesis, respiration and cell concentration. Yet, these are very important to understand since they set the foundations for the following classes. The course is led in a fairly classic way, with 16 hours of lectures, followed by several lab sessions. All the course material is available on a Moodle e-learning platform, and the teacher even added extra self-evaluation MCQ. However, students do not seem to find much interest in them. At the end of the course, the students take a final test. The large number of students and the limited number of teaching hours make it difficult to change this structure or even provide a personalized follow-up. The challenge is therefore to find a way to motivate students to work on their own, beyond classroom hours, and help them remember the terminology and better understand the biological phenomena.

EscapeCell

EscapeCell is composed of three elements: a set of mini-games to review the terminology and concepts for each chapter, a gamification module integrated into the e-learning platform that encourages the students to complete the mini-games and several references to the games in the course material and during the lecture. Let us describe each of these in detail.

Fig. 1. Mini-game 1 -Operation photosynthesis

The course is comprises of an introductory chapter and five other chapters and one mini-game has been designed for each chapter. Thus, EscapeCell includes five minigames, three of which have been developed.For example, the concepts in the chloroplast and plastids chapter were used to create the mini-game 1: Operation Photosynthesis (Figure 1). It is a puzzle-type game in which the students need to select the objects in the toolbox (left of the screen), that represent the elements in the chloroplast and correctly place them in the middle of the scene, to recreate the photosynthesis process. If the object is not positioned correctly, it flies back to its initial position in the toolbox. A non-player character, called "Blob", provides explanations to help the students throughout their mission (e.g., "it is too dark in here" to encourage students to switch on the light button that is necessary for photosynthesis). As students complete the scene, Blob moves forward on the bridge to materialize their progression. When the scene is complete, an animation shows the photosynthesis process which converts light into chemical energy that is then stored in organic compounds and releases gas. Three bonus information modules are hidden in the game. They provide extra information about the photosynthesis process. These modules can be unlocked by clicking on specific parts of the scene (e.g., lever and battery on the top right of the first picture of Figure 1). Similar mini-games were created for chapters 2 and 3 (Figure 2). The mini-games for the last two chapters were designed but are not yet fully developed. The look of the course space on the e-learning platform was completely transformed. Figure 3 shows how the artwork from the mini-games was used to illustrate the different sections of the course. When students click on the chapter related to chloroplasts and plastids (illustrated by a green Blob), for example, they have access to the slides used by the teacher during the lecture , the first mini-game in Figure 1, and the MCQ related to this chapter. We also developed a custom gamification module for the platform that shows if the students have completed the mini-games and the MCQs. This completion meter is presented in the form of a plant that gradually develops. A new branch grows each time the student completes a mini-game. On each branch, a small flower appears for each bonus information module the student has discovered, and a leaf will sprout if the student completes the MCQ related to the chapter. Students see this completion meter as a progress bar, an avatar and a set of badges, at all times, on the top right of their course space.

Finally, the teacher modified her course to integrate the game in three ways. First of all, she completely changed her slides by using the mini-game graphics to illustrate the elements in a plant cell and the biological phenomena. Second, she strongly encouraged the students to complete the mini-games and the MCQs at the beginning of each lecture. While undertaking this, she would also show the plant completion meters of the entire promotion of students on the board. Each student could see the plant associated with their name and compare it with others. This was intended to encourage students to work between lectures. Finally, the teacher also programmed a 2-hour "autonomous lab session" before the final exam, during which the students were asked to play or replay the mini-games and do the MCQs for each chapter.

Design Method

The mini-games, the gamification module for the e-learning course and their integration in the lecture were designed during the Ludifik'action professional training session, provided by the university [START_REF] Marfisi-Schottman | 10 Commandments of the Serious Game Padawan: Lessons Learned After 4 Years of Professional Training[END_REF]. In addition to the two trainers, who specialize in SG design, the teacher was accompanied by a team of two educational engineers, a graphic designer, a multimedia developer, and an audiovisual artist who recorded the Blob's voice. The Moodle plugin was also developed by a research engineer. Several groups of students were involved in the design process by testing paper prototypes of the minigames.

4

Experimentation

Hypothesis

The experimentation aims to measure if EscapeCell improved students' learning performances in the final exam. A second objective is to investigate the influence of specific game design elements such as Blob and bonus information modules. Based on the research objectives, we established the following hypotheses:

• H1: EscapeCell enhances students' performance in the final exam.

• H2: The presence of Blob, the non-player character, helps and guides students throughout the mini-games.

• H3: The bonus information modules, hidden in the mini-games, increase students' results in the final exam.

Experimental Protocol

This study follows the General Data Protection Regulation (GDPR), which serves as the legal reference for personal data protection in Europe. The data registration for this study was submitted to the Data Protection Officer at the University of Strasbourg.

To examine H1, we conducted a comparative study between this year's and last year's results of the final exam. It should be noted that the content of the course, the teacher, and the exam were identical in both years. The difference is that last year's students (n = 133) only followed the classic course before taking the final exam, whereas this year's students (n = 117) also engaged in the EscapeCell SG and Gamification. The mini-games could be played individually or in groups on computers or smartphones.

To examine H2 and H3, this year's students were asked to answer a set of questions after completing each mini-game. For each of the five following affirmations, they needed to indicate whether they agreed or not on a 5-point Likert scale:

• A1. The mini-game is easy to use.

• A2. The game design motivated me to play.

• A3. Blob helped and guided me.

• A4. The mini-game helped me better understand the course content.

• A5. The mini-game helped me better understand the biological phenomenon.

At the end of the semester course, the students were also asked to fill in a questionnaire that provided us with information on their profile (age, sex, gaming habits) and specifically measured their learning experience in SGs using a Learner Experience Questionnaire developed by Liu [START_REF] Liu | Évaluer l'expérience d'apprentissage pour un design écologique dans les Serious Games éducatifs sur appareil mobile[END_REF]., Several usage tracks were also retrieved from the e-learning platform, such as the number of times the students completed a mini-game and the number of bonus information modules they discovered. SPSS (Statistical Package for the Social Sciences) version 27 was used for data processing in this study.

5

Results of the Study

The usage tracks show that 88 out of 117 (around 75%) completed at least one minigame and 66 (around 56%) completed all three mini-games. 40 students also played the mini-games several times. This is already a positive result, given the fact that the minigames were not mandatory.

5.1

Results for H1: Effect of EscapeCell on the Final Exam Results

Table 1 presents a comparative analysis of the final exam results between the control group and the experimental group that used EscapeCell. The control group obtained a mean score of 13.65/20, with a standard deviation of 3.19, denoting a moderate spread of scores around this mean. On the other hand, the experimental group showed a higher mean score of 14.46/20. In addition, this group had a standard deviation of 2.6, indicating smaller differences in scores around the mean as compared to the control group. This lower standard deviation suggests less variability in the performance of the students who used EscapeCell. In order to analyze the significance of this difference, we examine at first the distribution of the data, then select the most suitable comparison test. Figure 4 shows that the scores of the two groups slightly deviate from a normal distribution and the Kolmogorov-Smirnov test shows that the p-value of two groups is less than 0.05, which indicates the observed data didn't follow a normal distribution [START_REF] Tchibozo | Introduction pratique aux méthodes quantitatives en Sciences de l'éducation et de la formation[END_REF]. We therefore apply the Mann-Whitney test, the result indicates p = 0.026, which is less than 0.05 and the difference between the means of the two groups is significant. Therefore, we can confirm H1: EscapeCell has led to an improvement in student performance in the final exam in this study. In terms of game design, we are interested in the role Blob plays in the game and if he acts as a facilitator in the students' gaming process. The results from the correlation analysis of the questionnaires indicate a positive correlation between Blob's perceived usefulness (affirmation A3) and the mini-games' perceived ease of use (affirmation A1). The presence of Blob, therefore, seems to facilitate the use of the three minigames. However, as shown in Table 2, there are some notable differences among the mini-games. Blob seems especially useful and well-designed in the second and third mini-games and, in the third mini-game, Blob's perceived usefulness (affirmation A3) is even correlated to the fact that students understand the course content better (affirmation A4). This suggests that the presence and actions of Blob may have enhanced the usability of the game for students, making the gaming experience more intuitive and enjoyable. As such, Blob could facilitate student interaction with the game and could potentially contribute to improving learning outcomes. These results also provide us with insight into how the mini-game 1 could be improved by taking an example of what Blob does in the mini-game 2 and 3.

Results for H3: Effects of the Bonus Information Modules on the Exam

The number of bonus information modules discovered by students is positively correlated with the perceived ease of use (affirmation A1) of mini-game 2 (rs = 0.297, p < 0.05) and mini-game 3 (rs = 0.380, p < 0.01). Interestingly, students who unlocked more bonus information modules also achieved higher scores on the MCQ related to each chapter (rs = 0.320, p < 0.01). The results further indicate that the MCQ scores are significantly associated with the student's final exam grade (rs = 0.296, p < 0.01). In other words, the more students discover bonuses, the better they are at the MCQ. Contrarily, there is no correlation between the number of bonuses a student receives and their final exam scores.

When we look at the students' profiles, it appears that the frequency with which students play video games (gaming habits) has a positive influence on the number of bonuses they discover. Indeed, students who are casual to hard-core gamers demonstrate a higher propensity to unlock bonus in the mini-games. There is, however, no correlation between the frequency with which students play video games and their MCQ scores. This suggests that, although students may derive additional value from these mini-games, it does not necessarily guarantee a high performance in the final exam. 204 Perceived ease of use for Mini-game 1 0.125 Perceived ease of use for Mini-game 2 0.297* Perceived ease of use for Mini-game 3 0.380** **The correlation is statistically significant at the 0.01 level. *The correlation is statistically significant at the 0.05 level.

Limitations

Even though this year's exam results are very encouraging for H1, this could be due to an overall better level of the students, a pre-test is required for further study. The teacher did notice that this year's promotion was "particularly motivated and pleasant". We could argue that their pleasantness and motivation could be due to EscapeCell and the fact that the teacher visibly went out of her way to provide a motivating experience by setting it up. In addition, only 3 out of the 5 mini-games were finalized this year, so the final exam results could be even better with all 5 games. However, this hypothesis remains to be validated next year.

The statistics concerning the effectiveness of the game mechanics (Blob and bonus information modules) are exploratory. They mostly rely on the answers on the Likert scale, provided by the students, to the 5 affirmations right after each game. However, these affirmations could have induced a confirmation bias. In addition, participation in the EscapeCell is voluntary, and only 66 out of 117 students answered these questionnaires. Further experimentation should be led to confirm those hypotheses by comparing EscapeCell with and without these game elements.

6

Conclusion

In this study, the integration of EscapeCell (composed of several mini SGs and a gamification module) can enhances the students' performance in the final exam. This result could be attributed to two circumstances. Firstly, this improvement could be due to the supplementary work undertaken by students in the experimental group (who used EscapeCell), compared to those in the control group. Indeed, these students had the opportunity to apply their course knowledge within the game, which further consolidated their understanding. Secondly, translating course content into a gamebased context might have enhanced the students' engagement and interest, leading to a more proactive learning approach. This was the initial objective of the teacher. The engaging and fun nature of the game could have helped students, who may have not been attentive during traditional classroom sessions, to actively participate. Moreover, the non-player character, called Blob, who assists to players, facilitates their procession through the mini-games. The presence of this guide making the game more accessible and engaging, especially for those who may be new to gaming. Besides, the hidden bonus information modules introduce an aspect of rewards (progress bar). They motivate students to dive deeper into the game, thereby increasing their interactions and engagement with it. This could potentially lead to a more comprehensive understanding and internalization of the educational content presented within the game. However, the number of bonuses the students unlocked does not correlate with their final exam scores. EscapeCell, therefore, serves as a valuable supplement to conventional instruction. It provides a complementary teaching method to enhance understanding of the course material. These inferences are based solely on this study, and further research is needed to confirm them.

Fig. 2 .

 2 Fig. 2. Mini-game 2 -Mission respiration and Mini-game 3 -Vacuole commando

Fig. 3 .

 3 Fig. 3. Integration of the game to the e-learning platform

Fig. 4 . 2

 42 Fig. 4. Kolmogorov-Smirnov test for two independent groups

Table 1 .

 1 Comparison of students' final exam across the two groups

	Group	n	Mean grade	Standard deviation
	Control group	133	13.65	3.19
	Experimental group	117	14.46	2.6

Table 2 .

 2 Impact of Blob in three mini-games.

	A3. Blob usefulness	Mini-game 1	Mini-game 2	Mini-game 3
	A1. Mini-game ease of use	0.349**	0.427**	0.525**
	A2. Game design	0.243	0.349**	0.407**
	A4. Comprehension course	0.161	0.199	0.290*
	A5. Phenomena understanding 0.101	0.169	0.551
	**The correlation is statistically significant at a 0.01 level.
	*The correlation is statistically significant at a 0.05 level.

Table 3 .

 3 Impact of Bonus Information Modules

	Impact of bonus	Number of discovered bonuses
	Gaming habits	0.220*
	MCQ scores	0.320**
	Scores of final exam	0.

Acknowledgements

This project was financed by Le Mans Université, France. We specially want to thank the entire conception and development team: Tiphaine GALPIN, Tiphaine INGUERE, Raphaël LALANNE, Fréderic LABRE, Franck VARET and Mohamed Hamza FALIH.


Lucie Abouaf
email: lucieabouaf@gmail.com

A Vighetto

E Magnin

A Nove-Josserand

S Mouton

C Tilikete

Primary Position Upbeat Nystagmus in Wernicke's Encephalopathy

for morbid obesity. In the subsequent 4 months, he suffered from recurrent and intense vomiting, losing 40 kg. Asymptomatic hypokalemia and hypomagnesemia were discovered and supplemented. At this time, systematic oral vitamin therapy was begun. One month later, he started to describe blurred vision and vertical oscillopsia. Neurological examination revealed ataxia and nystagmus. Standard biological screening and vitamin dosage were normal except for thiamine, which was just above the inferior limit. His CT scan and brain MRI were normal. Wernicke's encephalopathy was suspected and ataxia improved following the introduction of parenteral vitamin therapy. Because of persisting oscillopsia, the patient was referred to our unit.

Neuro-ophthalmological examination disclosed upbeat nystagmus in the primary position of gaze and gaze-evoked nystagmus in lateral gaze, with an oblique direction due to upbeat nystagmus. PPUN was rapid, persistent in up-and-down gaze, and absent in the supine position. Examination disclosed a postural ataxia originating in both a somatosensorial deficit with abolished tendon reflexes and cerebellar syndrome. Electroneuromyog-Dear Sir, Primary position upbeat nystagmus (PPUN) is a rare nystagmus observed in neurological diseases. Although Wernicke's encephalopathy is one of the classical etiologies of PPUN [START_REF] Leigh | The Neurology of Eye Movements[END_REF] , clinical reviews of this pathology do not precisely describe PPUN as a frequent neuro-ophthalmological manifestation [START_REF] Cogan | Ocular signs of Wernicke's disease[END_REF] . The neuro-ophthalmological signs reported more frequently are bilateral abduction deficits due to VI nerve palsies, and vertical or horizontal gaze-evoked nystagmus.

We report here two cases in which PPUN was the predominant manifestation of Wernicke's encephalopathy.

Case Reports

Case 1

The first case involves a 44-year-old man with a history of morbid obesity, sleep apnea, high blood pressure, high blood cholesterol, surgery of testis cancer 5 years ago, and glucose intolerance. Ongoing treatment included atorvastatin, omeprazole and diltiazem. He was admitted to our neuro-ophthalmology unit for further evaluation of oscillopsia. Six months before, he had undergone sleeve gastrectomy raphy confirmed a sensitive and motor neuropathy compatible with a deficiency etiology. Parenteral thiamine therapy was reinforced and contributed to a subjective improvement of ataxia and oscillopsia.

One year after the bariatric surgery, the PPUN had disappeared and we observed a transition to downbeating nystagmus.

Case 2

The second case involves a 51-year-old man with a history of chronic alcoholism, seizure after alcohol weaning and untreated high blood pressure. Ongoing treatment included paroxetine, fenofibrate, alprazolam and nebivolol. He was admitted to our hospital for confusional syndrome in the context of anorexia and vomiting. Confusion was associated with hallucinations and false recognitions. Clinical examination disclosed a static cerebellar syndrome and manifestations of a pre-delirium tremens state. Although the patient did not complain of oscillopsia, oculomotor examination revealed an upbeat nystagmus in the primary position of gaze and gaze-evoked nystagmus in lateral gaze, with an oblique direction due to upbeat nystagmus. PPUN was not influenced by vertical gaze positions, convergence or the Upbeat Nystagmus in Wernicke's Encephalopathy Eur Neurol 2011;65:160-163 161 supine position. In the context of severe alcoholism, the clinical presentation was suggestive of Wernicke's encephalopathy and Korsakoff's syndrome. Parenteral thiamine and pyridoxine therapy was provided. His CT scan was normal. Brain T2 and FLAIR MRI revealed multiple hypersignals involving the mamillothalamic nuclei, trigone, inferior colliculi and posterior medulla. There were contrast enhancements of mammillary bodies and inferior colliculi ( fig. 1 ). These abnormal signals were suggestive of Wernicke's/Korsakoff's syndrome. Six months later, ataxia and PPUN had improved, but despite long-term vitamin supplementation, his cognitive state had not changed.

Eye Movement Recording

The patients underwent eye movement recording using infrared video-oculography (25 Hz frequency; Synapsys , Marseille, France).

PPUN showed a linear slow phase in both patients, with a mean velocity of 30°/s in both cases ( fig. 2 ).

In case 1, the nystagmus did not change with eye position, but was dampened in the supine or leaning forward position. In case 2, the nystagmus decreased in the downward eye position and increased in the supine position (up to 40°/s). Vertical smooth pursuit (amplitude: 20°, frequency: 0.15 Hz) showed absent upward slow movements and normal downward movements in both patients. Due to the nystagmus, the mean gain of upward smooth pursuit was negative: -0.50 in case 1 and -0.94 in case 2; downward gaze was 1.24 in case 1 and 1.50 in case 2. Horizontal sinusoidal chair rotation (max velocity: 60°/s, frequency: 0.10) with the head in a 90° tilted position induced vertical vestibulo-oc-ular reflex with a mean gain of 35% up or down in case 1 and 50% up or down in case 2 (taking the downward slow phase into account).

Discussion

We report here the cases of two patients presenting with PPUN as a main manifestation of Wernicke's encephalopathy.

PPUN is an uncommon form of central nystagmus observed in different neurological diseases. Upbeat nystagmus might present linear, such as our 2 cases, or exponential slow phases. It is usually enhanced in upgaze and sometimes by convergence, but most often is not modified in lateral gaze. Finally, in many of the described cases, PPUN is dampened in the prone or supine head position, and may even reverse [START_REF] Hirose | Upbeat nystagmus: clinicopathological and pathophysiological considerations[END_REF][START_REF] Pierrot-Deseilligny | Vertical nystagmus: clinical facts and hypotheses[END_REF][START_REF] Fisher | Primary position upbeating nystagmus. A variety of central positional nystagmus[END_REF][START_REF] Pierrot-Deseilligny | Upbeat nystagmus due to a small pontine lesion: evidence for the existence of a crossing ventral tegmental tract[END_REF][START_REF] Baloh | Spontaneous vertical nystagmus[END_REF] .

Its clinical importance usually lies in the fact that the majority of the reported cases involve a brainstem focal lesion that must prompt access to MRI in these patients. Two main lesion sites have been described: the paramedian pars of the caudal medulla and the paramedian rostral pons [START_REF] Hirose | Upbeat nystagmus: clinicopathological and pathophysiological considerations[END_REF][START_REF] Pierrot-Deseilligny | Vertical nystagmus: clinical facts and hypotheses[END_REF][START_REF] Tilikete | Upbeat nystagmus from a demyelinating lesion in the caudal pons[END_REF] .

Anatomoclinical analysis of patients with focal lesions led to the hypothesis that PPUN is a consequence of an imbalance in the neural networks involved either in vertical slow phases, mainly the vertical vestibulo-ocular reflex and smooth pursuit, or in the vertical gaze holding system, namely the vertical neural integrator [START_REF] Leigh | The Neurology of Eye Movements[END_REF] . The relative deficit of the upward-directed tonic activity as compared to downward would result in a downward drift with a corrective upward quick phase. According to recent hypotheses, the medullar lesions would impair a feedback loop receiving afferents from the vestibular nuclei and projecting to the flocculus [START_REF] Pierrot-Deseilligny | Vertical nystagmus: clinical facts and hypotheses[END_REF][START_REF] Pierrot-Deseilligny | New insights into the upward vestibulo-oculomotor pathways in the human brainstem[END_REF] . The pontine lesions would impair one of the efferent tracts from the vestibular nuclei to the oculomotor nuclei [START_REF] Pierrot-Deseilligny | Vertical nystagmus: clinical facts and hypotheses[END_REF][START_REF] Fisher | Primary position upbeating nystagmus. A variety of central positional nystagmus[END_REF][START_REF] Pierrot-Deseilligny | Upbeat nystagmus due to a small pontine lesion: evidence for the existence of a crossing ventral tegmental tract[END_REF] . The specific modulation of PPUN by the head position suggests the implication of an otolith-related component in the genesis of the nystagmus in some patients [START_REF] Fisher | Primary position upbeating nystagmus. A variety of central positional nystagmus[END_REF][START_REF] Pierrot-Deseilligny | Upbeat nystagmus due to a caudal medullary lesion and influenced by gravity[END_REF][START_REF] Janssen | Upbeat nystagmus: clinicoanatomical correlation[END_REF] . This otolithrelated function is attributed to the crossing ventral tegmental tract, whose role could be to counteract the gravity pull in the upright position [START_REF] Pierrot-Deseilligny | New insights into the upward vestibulo-oculomotor pathways in the human brainstem[END_REF][START_REF] Pierrot-Deseilligny | Effect of gravity on vertical eye position[END_REF] . According to this model, case 2 could have lesioned the pontine vestibular efferents without the cerebellar loop, which might account for the absent positional modulation. In contrast, case 1 could have lesioned the medulla with impairment of the cerebellar feedback loop, which could account for the gravity modulation.

PPUN have also been described in more diffuse pathologies such as meningitis, encephalitis, intoxication and Wernicke's encephalopathy [START_REF] Leigh | The Neurology of Eye Movements[END_REF] .

Gait ataxia, confusional state and oculomotor manifestations are the clinical triad of Wernicke's encephalopathy. Various oculomotor signs have been described in Wernicke's encephalopathy, such as nystagmus (gaze-evoked, horizontal or vertical), six nerve palsies (which can be bilateral), third nerve palsy, paralysis of conjugate gaze and reduced gain of optokinetic nystagmus [START_REF] Cogan | Ocular signs of Wernicke's disease[END_REF] . In clinical studies, oculomotor signs are present in 93% of the cases [START_REF] Harper | Clinical signs in the Wernicke-Korsakoff complex: a retrospective analysis of 131 cases diagnosed at necropsy[END_REF] , but clinical descriptions of the different types of nystagmus are lacking. The incidence of PPUN in these series is not known. On the other hand, adding our 2 cases, Wernicke's encephalopathy seems to represent 20% (12 cases) of the etiologies [START_REF] Kesler | Acute ophthalmoplegia and nystagmus in infants fed a thiamine-deficient formula: an epidemic of Wernicke encephalopathy[END_REF] . Furthermore, as in our 2 cases, PPUN may be the chief sign leading to the diagnosis.

Among the 58 cases of reported PPUN, transition from upbeat to downbeat was observed in 5 cases, 4 of them following Wernicke's encephalopathy [START_REF] Suzuki | Transition from upbeat to downbeat nystagmus observed in a patient with Wernicke's encephalopathy[END_REF][START_REF] Rousseaux | Upbeat and downbeat nystagmus occurring successively in a patient with posterior medullary haemorrhage[END_REF][START_REF] Sakuma | Primary position upbeat nystagmus with special reference to alteration to downbeat nystagmus[END_REF][START_REF] Kastrup | Presumed pharmacologically induced change from upbeat-to downbeat nystagmus in a patient with Wernicke's encephalopathy[END_REF] . This clinical finding might then be considered as a specific feature of PPUN associated with Wernicke's encephalopathy. According to recent models of vertical nystagmus (4), downbeat nystagmus is explained by flocculus/paraflocculus dysfunction. We could suggest that the disappearance of upbeat nystagmus due to improvement of metabolic brainstem lesions unmask an underlying downbeat nystagmus due to persisting cerebellar dysfunction. There is currently no explanation concerning the predilection of these diencephalic and brainstem structures in thiamine defi-ciency. PPUN (and transition to downbeat nystagmus) might be explained by altered pathways involved in upward (and downward) vestibulo-oculomotor pathways both at the level of the fourth ventricle floor and cerebellar vermis.

Disclosure Statement

The authors declare that they have no conflicts of interest. In each column, eye movement recordings are successively represented for different gaze or body positions and different times. Note the primary position upbeat nystagmus, with the linear slow phase decreasing in the lying down position and changing to downbeat nystagmus with time in case 1, while increasing in the supine position in case 2.

Fig. 1 .

 1 Fig. 1. Cerebral MRI of case 2. Axial FLAIR sequence at the brainstem level shows hypersignals of the periaqueductal area (A). Axial FLAIR sequence at the diencephalic level shows hypersignals of the paramedian thalamic nuclei (B). Axial T1-weighted image with gadolinium shows bilateral and symmetrical enhancement of the mammillary bodies (C).

Fig. 2 .

 2 Fig. 2. Vertical eye position of the right eye is plotted against time (case 1: first column; case 2: second column).In each column, eye movement recordings are successively represented for different gaze or body positions and different times. Note the primary position upbeat nystagmus, with the linear slow phase decreasing in the lying down position and changing to downbeat nystagmus with time in case 1, while increasing in the supine position in case 2.

Eur Neurol 2011;65:160-163


Ariel Colonomos
email: ariel.colonomos@sciencespo.fr

The National Interest and Global Justice: Contradictory Terms, Incomparable and Non-commensurable Goods, Yet Compatible?

Keywords: International politics, International relations theory, Global justice, National interest, Commensurability, Realism

Prima facie, the pursuit of national interest stands in contradiction with the rules of global justice. Indeed, the former relies upon selfishness and the maximization of national utility, while the latter presupposes distributive measures at the global level that exercise some constrain on state behavior. However, these two notions are open to interpretation and, sometimes, even lack clarity. This paper will look for clarification and will ask whether it is possible to go beyond the radical difference between those two logics. I will start by underlining the reasons why the national interest and global justice are in contradiction with each other. Although they are not commensurable, the paper will then argue the two can be compatible in specific equilibriums of international politics, I will refer to as the "rationalist" and the "revolutionist" modes. Finally, the paper will discuss whether, in the best of all possible worlds, we should strive for this compatibility.

The speech by the US representative is particularly strange to me; she gave her speech as if she was Mother Teresa herself. Please, remember which country you represent! Please, remember the track record of your country.

Vitaly Churkin, Russia's representative at the UN, responds to Samantha Power at the Security Council and to her accusations regarding Russia's involvement in Syria (New York, December 2016).

Introduction: A Dyadic Relationship

The national interest and global justice are two frameworks that both come from rich and sometimes complex traditions and have travelled along different historical and conceptual paths. These trajectories, however, overlap, since, in theory as well as in practice, the national interest and global justice are deeply entangled. Indeed, they form a complex dyad and are complimentary to each other. Whether they stand in opposition to each other or they are two constitutive parts of one single foreign policy, one presupposes the other.

The opposition thesis is very well-known. There is a gap between the national interest and global justice. It is often believed that a country following its national interest cannot foster global justice. Conversely, because it must also provide care to other people than its own, a state that acts in favor of global justice would have to put aside its national interest. Such gap does not preclude the fact that one is the anti-thesis of the other and that therefore there is a strong connection between the two.

The case for compatibility has also been made. Combining the national interest and global justice, or rather "reconciling" the two, is a matter of pragmatism, because this dual approach would grant legitimacy to political decision. Domestically, a state is responsible for the security of its citizens. Internationally, if it wants to foster alliances, a powerful state has to support global norms and values. Normatively, we may also argue that, provided it has the capabilities to fulfill these two roles, a state carries the obligation to do so. This paper will explore the two possibilities, the gap thesis and the compatibility scenario, and will shed light on their different facets. Despite the gap that stands between the national interest and global justice, it will make the case the two are, under certain conditions, compatible. We may then wonder if this is a solution to the problems that we face in the realm of global politics.

While the ideas of "interest" and "justice" are about as old as the humanities and the social sciences are, the "National interest" and "Global justice" are more recent. The national interest stands as the oldest of the two, and this paper will sketch out what are its most well-known historical and political interpretations. The case of global justice is different. As Charles Beitz underlines, it appears as a new concept and a more novel field of research (Beitz 2005, 12). Despite this historical difference, these two paradigms have been rapidly confronted to each other, in the field of theory as well as in practice.

It must be noted that the two concepts of global justice and national interest are western-centric. 1 Of course, knowledge crosses the borders that separate western societies from non-western countries. Moreover, non-western countries are part of 1 As I will show in the paper, although we can trace the roots of the Realism/Idealism dispute back in Europe and notably in Germany, both frameworks, the National interest and Global justice, as well as their dyadic relation, originate, essentially, in the US (and to a much lesser extent in the UK). They are constitutive parts of the IR academic debate and mirror the history of US foreign policy. The National Interest and Global Justice: Contradictory Terms,…

the leading international organizations and use diplomatic codes that are shared internationally. Indeed, integrating the global scene presupposes to master these codes, and it is a fact that these two notions are part of a debate occurring also in non-western parts of the world. However, whether these ideas have the same meaning that prevails in western countries, this, of course, remains to be seen. 2 The question of meaning is extremely important and complex, as, even within western circles, the national interest and global justice are interpreted in different ways. How could it be otherwise? The national interest and global justice are multifaceted. The national interest is both used an explanatory paradigm and a normative concept, which has, in these two domains, different substantive contents. Global justice is mostly a normative concept, but in some instances, at least minimally, it relies upon empirical observations and social explanations. Therefore, it does not come as a surprise that we find numerous interpretations of both ideas and frameworks. Moreover, as a dyad, the question of the relation between the national interest and global justice is subject to different interpretations, in the field of International Relations (IR), as well as in normative theory.

My analysis is, therefore, multilayered and brings together the social sciences (mostly IR) and normative theory. The relation between the national interest and global justice is, essentially, I argue, an interdisciplinary question and has implications for both IR and normative theory. It is also a crucial issue in the field of international normative theory that brings together these disciplines.

I explore, in this paper, the confrontation between different interpretations of the national interest and global justice and I discuss the political, normative and epistemic problems that the question of the relation between the two raises. The paper is divided into two large parts. The first part highlights the gap between the two notions. This radical difference has two facets. This is the most widely shared thesis both in classical IR and normative theory; my paper, first, shows how they stand in contradiction to each other. Second, it is important to discuss the main epistemological divides between the two, and I will argue that the national interest and global justice appear as two noncommensurable and incomparable goods. While it moves beyond the gap thesis, the second part of the paper also includes two sections. In the first section, I show that despite this opposition and the non-commensurability problem, we may find reasons explaining why, from an international theory perspective, the national interest and global justice could be compatible. This space for compatibility lies at the intersection of theory and practice. Finally, in the second section, I ask whether, normatively, the compatibility scenario is a state of world affairs we may want to strive for. This section explores the tensions between the theory of classical realism and global justice claims. Since classical realism has greatly influenced both explanatory IR studies and normative thinking applied to international politics, this preliminary analysis is essential.

R E V I S E

The Realism/Idealism Debate

The theoretical and practical opposition between the national interest imperatives and global justice is rooted in an old debate, i.e., the historical tension between Realism and Idealism.

As a school of thought, Realism appears in the interwar period and strongly develops, later, in the aftermath of World War Two. The writings of E. H. Carr and Hans Morgenthau stood both as a call addressed to scholars within the newly created filed of international relations as well as to practitioners of international politics. Realists had a mission and the message they conveyed was very clear: International law and ethical claims in international affairs are misleading and have a negative impact on the course of world affairs (Carr 1937; Morgenthau 1948). According to Carr and Morgenthau, de facto, law and ethics are inappropriate tools when explaining international politics. Moreover, they claimed that norms do not play such a significant role in international politics. However, from a normative perspective, classical realists also claimed that, if they were to play a role, this would threaten the stability of international politics and the survival of states.

Therefore, classical realism and, more generally, at its origin, the field of IR in political science stood as a reaction against international law. Interestingly, Morgenthau was originally a lawyer who migrated from Germany and, once he established himself in the US, became one of the founders of this newly created field. During the first decades of the Cold War, he had been of its most influential theorists, if not its most influential thinker.

Consequentialism Versus Principled Approach

Morgenthau's thinking is both explanatory and normative. Indeed, he not only wanted to explain how states behave, he also set some political principles that ought to define political action. According to Morgenthau, along with the maximization of power, pursuing the national interest is an imperative (Morgenthau 1951; Beitz 1979, 20). A state's national interest lies in securing its security and identity. Preserving the state's territorial identity is a primary goal. Keeping its prestige in the international arena is part of the secondary goals of the national interest. Since it was challenged by other states and, as a superpower, was responsible for the survival of the "free world," this duty lied foremost with the US.

However, Morgenthau did not totally dismiss the role of international law, as, for him, "there must be certain rules of conduct defined beforehand, whose violation 1 3

The National Interest and Global Justice: Contradictory Terms,… would normally call forth certain sanction" (Morgenthau 1948, 210). Moreover, classical realism, and notably Morgenthau himself, was also influenced by ethical traditions. Realism in Morgenthau's terms is, indeed, consistent with a Weberian ethics of responsibility. More surprisingly, Morgenthau's thinking also echoes Aristotelian philosophy and its emphasis on virtues (Lang 2004). Indeed, the statesman must show his resolve and the strength of his will. Among Aristotelian virtues, we find temperance and prudence, and realists often valued prudence. As an example, we can see how Morgenthau criticized the US intervention in Vietnam, which he saw as the expression of a "persistent dilettantism" (Morgenthau 1965).

Morgenthau was mainly a pragmatic thinker who emphasized the role of the political: "the choice is not between moral principles and the national interest, devoid of moral dignity, but between one set of moral principles divorced from political reality and another set of moral principles derived from political reality" (Morgenthau 1951, 33). 3 When costs are high, state leaders do not follow international law. 4 In Realism, security trumps rights. Therefore, realism's main opponent is a principled approach to ethics. Kantianism or other deontological models would tie the hands of the political and would be an impediment to the pursuit of the national interest, as the former needs to be adaptive.

The "Is" and the "Ought"

Classical realists often refer to Hobbes and notably to the metaphor of the "gladiators" Hobbes used when characterizing states' behavior in the international arena (Hobbes 1963, 144). Whether, it is possible to infer from Hobbes's state of nature social laws that would apply to international politics, this is questionable; however, the Hobbesian framework is an illustration of realists' main concern. Realists underline the essential role of the state in international relations and draw the "ought" from the "is". Throughout the 20th century, the state has been, indeed, the dominant player on the world stage and, according to realists, it should remain at this place. Therefore, global justice frameworks would threaten this primacy as supranational norms would constrain states' political strategies.

"Balance of power" stands as a better regulatory tool than international norms (whereas according to the liberal internationalist tradition, norms have a stabilizing function). Realists have often been criticized for their idolatry of the state. However, they claim, states are rational and, therefore, because they understand what are their interests, they create a balance of power. In contradistinction, international law and therefore global justice lead to instability. The injunctions of legalism and moralism are dangerous as, normally, states pursue their national interests. For those that were tempted to follow moral and legal principles, they would be highly exposed as their competitors would take advantage of such naïveté. By setting international standards, whether in terms of economic distributive justice or in the field of war, those who support global justice want to limit the pursuit of states' interest because, at another level, this would hurt the well-being of individuals. This should come as no surprise, classical realism, and notably Morgenthau's offensive realism, is a source of concern for those ethicists who stand in favor of global justice.

R E V I S E

Realism appears as all the more problematic that the pursuit of the national interest can lead to war. Thucydides' analysis of the Peloponnesian war (Thucydides 2000) is a clear illustration of the perils of political decisions rooted in the pursuit of the national interest. 5 As all states want to pursue their interests, they are tempted to build up their armaments or make new alliances in the face of uncertainty, which could, eventually, trigger preventive wars.

Realists are aware of the "security dilemma" problem (Herz 1950; Jervis 1978). Those that favor Realpolitik and those scholars of IR who belong to the realist tradition have both criticized preventive war. According to Bismarck, preventive war is "suicide for fear of death". In the eve of the 2003 US intervention in Iraq, a "coalition for cautious realists" stood against the decision by the Bush administration to use force. 6 Indeed, realists are all the more aware of this danger, as they well know their own theory could eventually trigger unnecessary wars.

Notwithstanding, the emphasis that realists as well as neo-realists put on instrumental rationality remains the source of many concerns. For realists, preventive wars are anomalies: Rational leaders are expected to understand that engaging into hazardous wars is contrary to their nations' interests. But anomalies are part of our daily lives. Morgenthau, himself, expressed his skepticism, as he drew the line between the practice of politics and the ambition of science (Morgenthau 1946, 221): "No formula will give the statesman certainty, no calculation eliminate the risk, no accumulation of facts open the future. While his mind yearns for the apparent certainty of science, his actual condition is more akin to the gambler's than to the scientist's".

This emphasis on rationality stands in contrast with another factual analysis of the behavior of states. According to realists, the quest for prestige is inherent to state behavior. Although defining precisely what is the nature of state's prestige is a true challenge, 7 reputation games are said to be inherent to interstate relations. In international politics, the most famous example is deterrence which has a regulatory function, but that can also be very dangerous. Deterrence also reinforces inequality between states.

The quest for prestige is a reason that could motivate states to develop nuclear armaments. Prestige and the willingness to pursue the national interest are important variables that explain the policy of Iran to develop its nuclear weapons. Realists such 6 With the exception of Mearsheimer, most signatories of this declaration were "defensive" realists. 7 Collective bodies are different from individuals. On reputation in the field of international politics, see Mercer (2010). 5 According to Thucydides, Athens's policy of building alliances and developing its armament was the "cause" that led to Sparta's attack. The National Interest and Global Justice: Contradictory Terms,…

as Kenneth Waltz have argued that if it developed nuclear weapons, Iran would pose no threat to international security (Waltz 2012). 8 This goes against international law and is therefore contrary to the aspirations of global justice. Nationalist bellicose policies also stand in contradiction with the very spirit of global justice. We witness another tension between the national interest and global justice. Both in the field of theory and in the field of practice (Realpolitik), realists often refer to the idealist tradition and therefore to global justice, as an irresponsible set of claims. They stigmatize the pretenses of those who are disconnected from the reality of international politics, those pure souls whose hands are not dirty. Worse than this "flight from reality" (Shapiro 2007), idealism is a "fig leaf". It is said to be dangerous, naïve or, sometimes, hypocritical.

A good reflection of this tension is the clash at the UN Security Council that opposed Samantha Power to the Russian representative over Syria and Russian bombings. 9 Vitaly Churkin, the Russian representative, mocked Power and her willingness to play "Mother Teresa," whereas according to him, US history was paved with gross violations of the major laws of war. There lies a gap between words and deeds. US policy would then be two-sided. In some instances, its discourse is inspired by liberal internationalism, while, in practice, the US follows what its leaders see as its national interest including in cases where human costs are very high. In the face of what is seen as the inherent hypocrisy of idealism and global justice, Realism along with its pursuit of the national interest is unapologetic and praises itself for being consistent with its premises.

Part 1 Section 2 Comparability and Commensurability Gaps

The US is a crucial case, as, indeed, its foreign policy includes these two aspects. However, whether empirically, logically and normatively, these two visions can be reconciled remains to be seen. In order to answer this question, we want to explore two issues. Are these two goods comparable? 10 Are they commensurable? Indeed, in order to reconcile the two goods, we often presuppose that they can be compared to each other and, eventually, can be measured according the same standards.

We can here draw a parallel with the issue of proportionality in warfare. According to its definition in international humanitarian law and its most common interpretation in jus in bello, the damages caused by the use of force, in this case mostly civilian deaths and the destruction of their properties, must not be excessive in relation to the concrete and immediate military advantage that is anticipated. 11 One of the main goals of the rules of war, whether in the just war tradition, in international law or in international humanitarian law, is to limit the use of force while 8 This is consistent with Waltz's neo-realist explanatory framework. See Sagan and Waltz (1995). 9 http://www.abc.net.au/news/2016-12-14/un-excha nge-saman tha-power -blast s-russi a-assad -over-alepp o/81192 36. 10 I define here as "goods" the ideas and values, as well as the different sets of practices that the National interest and Global justice inspire or are the reflection of. 11 https ://ihl-datab ases.icrc.org/custo mary-ihl/eng/docs/v1_rul_rule1 4. reconciling two values: on the one hand, humanity in the field of ethics and law, on the other hand, efficacy in the military and political fields. The rule of proportionality is a remarkable illustration of this attempt. However, both theoretically and practically, the arithmetic of proportionality is very problematic. One of the reasons of this challenge to use properly this norm lies in the difficulty to compare the two opposite types of consequences of military action (military advantage on the one hand, civilian losses on the other) and in the non-commensurability of the variables included in the proportionality calculus (Colonomos 2017b).

We are confronted to a similar problem in the case of the national interest and global justice. At least for powerful countries, global justice is often seen as a limit to the pursuit of the national interest. 12 From a consequentialist perspective, states would try to anticipate how global policy would affect their national interest. In order to reconcile the national interest with global justice, they would need to put into the same balance two different types of goods.

However, can they? As in the case of proportionality where the variable of the "military advantage" is very difficult to define, setting the proper terms for the relation between the national interest and global justice is problematic because of the lack of precision of at least one of these two terms. Indeed, following the advent of Realism, the national interest has been widely criticized in IR (Rochester 1978) for being a "vague" and "elusive" concept. 13

Synchronic and Diachronic Incomparability

Are the national interest and global justice comparable to each other? According to Ruth Chang, two goods are incomparable when no positive valuation holds between them (Chang 1997, 4). The Trichotomy thesis is often used to define comparability and incomparability: "if one item is neither better or worse than another, and yet the two are not equally good, nothing affirmative can be said about them: they are incomparable" (Chang 1997, 2013). 14 Of course, Bismarck would tell that Realpolitk is "better" than international law, because the latter leads to political mistakes. Symmetrically, Friends of the Earth activists would probably argue that nuclear weapons are "worse" than development aid. But, these judgments rely on preferences that are not established in terms of "covering value" (Chang 1997, 5). In the first case, we can merely say that security trumps rights, whereas in the second, justice trumps balance of power.

The national interest and global justice are incomparable. This is the case synchronically. If, at a given moment, we have the possibility to allocate funds to either 12 Some states might benefit from resources distributed according to global justice principles. However, even for poor countries, their policies could be affected in other areas such as security or environmental policy. 13 According to James Rosenau the national interest relies on elusive criteria and is "plagued by the absence of criteria for cumulating the interests once they have been identified" (Rosenau 1971, 243). 14 To these criteria "better than," "worse than" and "equally good", Chang adds another criteria: It is neither true or false that they stand in a positive value relation (indeterminacy). The National Interest and Global Justice: Contradictory Terms,… killer robots or famine relief, we make two different sets of scenarios and, although, we cannot compare the two because of the lack of covering value, we can choose one of them according to our preferences, our priorities and our own definition of what humanity or politics should be. One of the two scenarios might match those criteria, while the other would not (frequently, if one scenario matches our criteria, it is likely that the second won't). Comparability can also be tested diachronically. Can we establish that, over time, state A has elaborated a "better" policy than state B? Both states have had the choice between using realist and idealist policy tools. They tried to combine different sets of measure and, overall, the use of those foreign policy tools has yielded some comparable outcomes (in different areas such as security, the economy, the environment). Going back to the example of the US-Russia confrontation, US representatives could, eventually, agree that the pursuit of the national interest (including the willingness to pursue what a priori seemed to be the national interest) has led the US to commit some wrongs (e.g., in the case of Vietnam or the 2003 Iraqi war). However, they could claim that overall, the US historical record and its commitment toward the future show that the US is more responsible and committed to justice than Russia, notably in the field of human rights. Moreover, the US could argue that it is worried about its national interest not only because it cares about the social conditions in which its own citizens live, but also because it has a mission to police and save the world. 15 The same can be said about other states such as India, France or Brazil, representatives of each country can find good reasons to claim that, as compared to other states, their national history is "better".

We frequently make intuitive judgments about the behavior of states and set comparisons. However, this example shows that, since global justice and the national interest are not comparable to each other, measuring the moral and political worthiness of states' policy is difficult. Ultimately, it can be possible to assess the outcome of different foreign policies, using economic or political criteria. However, it is hardly possible to measure the relative weight of global justice concerns and to put them in balance with the imperative of pursuing the national interest.

Epistemic Non-commensurability

If we were to say that global justice policies are better than national interest policies, in order to make this judgment, we would need to choose some common criteria. Of course, those, as Morgenthau, that support the national interest might say that, indeed, a foreign policy based on the pursuit of the national interest (and the maximization of power) is "better" than any other type of political initiative that would be based upon global justice principles, because it is more efficient. Global justice theorists would say that ethics is "better" than the selfish pursuit of the national interest because it is based on equal rights. However, there is no common measure between those two 15 Grotius, himself, grants special rights to powerful states that have the responsibility to save populations that are unjustly attacked, i.e., the former could lead preventive wars if they are threatened (Grotius 1925, 167). goods (Chang 2013, 5). This is problematic if we want to reconcile the two, since a common measurement would be required to find eventually a proper balance between the two. In order to reconcile the national interest and global justice, we should be able to test the pursuit of the national interest using normative criteria compatible with those of global justice. Vice versa, we would need to test global justice frameworks using the normative criteria that apply in Realism. However, this is hardly done, and, eventually, cannot be done.

Epistemically, these two goods are very different. Indeed, the disciplines where they are rooted are also different. On the one hand, the national interest is born at the onset of political science and IR. On the other, global policy pertains to a debate in the field of philosophy and law. Moreover, the national interest is a response to what was seen by Carr and mostly Morgenthau as the inconsistencies of international law and ethics. Realism ambitions to be a positivist approach to the study of international politics, whereas global policy is a normativist analysis of international relations.

Their analyses of the "international" starkly stand in contrast with each other. As a concept and a principle in foreign policymaking, the national interest applies at the state level. It also implies that the main actor of international politics is the state, i.e., it is "stato-centric". On the contrary, global justice goes beyond the stato-centric approach to international politics. Its most contemporary versions are cosmopolitan and individualist (Brooks 2008).

The two are divided by another type of commensurability gap. As in the case of proportionality, the values upon which these two are rooted are radically different (Colonomos 2017b). On the one hand, the national interest is inspired by values of efficacy, whereas on the other, global justice is rooted on values of dignity. Moreover, the national interest fails the test of the "separateness of persons", and this, clearly, appears to be problematic if we want to reconcile the two approaches (Rawls 1999, 13). The principle of separateness of persons rules out "justifying institutions on the grounds that the hardships of some are offset by a greater good in the aggregate". Even if the pursuit of national interest was to yield good results from the perspective of Realism, according to this principle, the stability of states could not justify the burden that some individuals would have to bear.

Part 2 Section 1 The Case for Flexibility and Compatibility

Both politically and epistemically, reconciling these two goods appears to be a challenge, if not an impossible task. However, there is a strong pressure to find ways to combine the two. Indeed, policy makers make attempts, they claim, to reconcile the pursuit of national interest with global norms. This, certainly, grants these leaders legitimacy. Indeed, the pursuit of the national interest is all the more "acceptable" in the eyes of civil society members, NGOs or the more general public, if it does not appear to stand against global justice (i.e., it does not hurt justice at the global level). Conversely, civil society activists, NGOs or norms entrepreneurs may want 1 3

The National Interest and Global Justice: Contradictory Terms,… to "convince" state leaders that their proposals are pragmatic. 16 Global justice ideas are all the more likely to be implemented by policy makers if they are not seen as a threat to the pursuit of the national interest. 17 Thus, both sides would have an interest in reconciling the national interest with global justice.

From a theoretical perspective, IR and, more generally, the social sciences may shed a different light upon this question. Indeed, despite realists' attempts to define the national interest and philosophers' claims about global justice, we lack a unique and consensual definition of what is the national interest and what is global justice. As for the former, this should not come as a surprise. Politics is an art, and therefore, state leaders ought to be free in setting what national interest they need to pursue. Therefore, the national interest is a highly contextual concept. As for the latter, although distributive justice is strong concern for those who study global justice, we find different approaches to justice in the normative literature on the subject whether they are grounded on deontological frameworks or utilitarianism, focus on rights or capabilities… As a consequence, as a dyad, the national interest and global justice include many different possibilities. Hence, precisely because of the plurality of these possible worlds, there might be some room for reconciliation between the two frameworks.

Contextualism in the Constructivist Approach

Constructivism has greatly developed over the last 20 years in IR and has become one of the predominant paradigms in the study of international/global politics. Constructivism originates in social theory and sociology, and IR adopted it in the early 90s, once it was already solidly established in the social sciences. From the perspective of constructivism, we may say, "the national interest" is a "social construction of reality". Therefore, defining objectively what the national interest is might not be possible. From a constructivist perspective, values and ideas orient the definition of interests. More broadly, this approach is consistent with Max Weber's own analysis of the relation between interests and values. Indeed, according to Weber, interests rule the world, however, ideas and world visions (therefore values) also impact interests (Weber 1993). Paradoxically, this approach would not stand in contradiction with the realist analysis. Indeed, according to Realism, the national interest is contextual, therefore must be coherent with its social environment. Policy makers, mostly Princes and executive leaders, decide what their state's interest is. This is part of what Morgenthau defines as the art of politics where the statesman acts like a "gambler" (Morgenthau 1946, 221).

Moreover, politically, defining one's interest is a signal that states send to both their own constituency and to other states. According to sociologist Richard Swedberg, interests act as "sign-posts," i.e., you follow your interest as if you were following a sign-post (Swedberg 2005, 95-96). It does not come as a surprise that discourses on 16 There is a large literature in IR on transnational actors, norms entrepreneurs and states. Some focus on the question of economic justice (O'Brien et al. 2000). In normative theory, some philosophers have tried to reconcile states' interests and goals with global justice concerns, for example, in the area of migration studies (Miller 2007). 17 In the case of chemical weapons, see Price (1997). the national interest are often made public. They are embodied in political programs and doctrines, discussed in the context of elections and are officially announced in diplomatic summits. This approach is also consistent with sociological and psychological accounts of international relations (Jervis 1970). Interests would be both a sign-post and, therefore a signal, in this case, a mode of indicating a route that one's state will follow in order to influence other states and also some domestic actors.

From a sociological perspective, global justice is also contextual. Although it is grounded on some universals, human rights, for example, its definition depends upon other variables such as the distribution of wealth and capabilities, culture and domestic pressure. It also depends on the prevailing and preexisting moral standards of those institutions, states or non-state actors, that announce publicly to act consistently with this rule.

Therefore, national interest and global justice are both markers of identity for states. They are important domestically and internationally. They are also interdependent. Indeed, usually, the national interest is defined as a preference for the national vis-àvis the international or the global. Conversely, global justice is also seen as a gesture that signals the willingness of a state to act in an altruistic mode on the international scene, it signals disinterest.

This duality parallels another distinction. The tension between the national interest and global justice is also the reflection of the distinction between "hard power" and "soft power". Indeed, at least according to the realist paradigm, the national interest should structure hard power. Conversely, global justice concerns might be part of "soft power". Both liberalism and constructivism would agree on the need for a state to include some provisions of global justice in order to foster a state's reputation on the international scene and to exert its power of attraction at the international level. 18 This is especially true for a superpower. This dual approach is a reflection of US strategy at least during the Cold War and its aftermath. 19 More generally, the US, often, argues that it is able to combine Realism and Idealism. 20 Therefore, if we adopt a contextualist approach, the national interest and global justice are necessarily intertwined. Both from an explanatory and a normative perspective, we may argue that the responsibility to pursue a policy that favors economic or political interests at the state level is imbricated with a country's status in the 18 This would be an explanation of state behavior. Eventually, liberal internationalists and constructivists would make a similar normative argument there: States should include global justice in their soft power policy. 19 The equilibrium between hard power and soft power is contextual. As opposed to Clinton's presidency, the Bush administration focused more on hard power. President Obama tried to restore soft power (and who knows what the actual president's views are concerning soft power). Whether this equilibrium between hard power and soft power and between the national interest and global justice makes sense in a non-Western environment such as China is a question we may ask at this conference. 20 When trying to explain what the Bush doctrine was, Condoleeza Rice wrote that "the old dichotomy between realism and idealism has never applied to the United States" (Rice 2008, 25). In the Obama administration, John Kerry stated that US foreign policy achieves greatness "only when it has combined realism and idealism". See Snyder (2009). The combination of realism and idealism is, for the US, a true "alignment of planets". The National Interest and Global Justice: Contradictory Terms,… world, and, therefore, eventually its effort to pursue global justice goals as a form of soft power without compromising its strategic goals defined in terms of hard power. From this contextual perspective, de facto, the national interest and global justice are compatible and "complimentary" to each other and states ought to find the proper balance between the two, depending on their capabilities and ambitions in world politics.

The Compatibility Thesis: an IR Systemic Perspective

Both according to constructivism and realism, the national interest and global justice are contextual and intertwined. According to realism, following the national interest is a state priority. However, global justice concerns also need to be addressed.

According to constructivism, norms orient the definition of interests. Therefore, the national interest is socially and historically contingent. From this perspective, ideas about global justice might orient the national interest, i.e., state leaders might believe that it is in their interest to limit their hard power and rather use soft power tools to maintain or improve the status of their country in the world. Liberalism would also consider that major powers, in order to maximize their interests, would also need to integrate global justice concerns, indeed ideals, from this perspective, should orient state strategy and its relations with other state units.

It is easier for a superpower to pursue this strategy, because it has the capabilities to do so and because power, traditionally, has been defined as the capacity to orient the behavior of other states. However, this is not only derived from the power of the state and its history. The national interest global justice nexus is itself contextual, as this relational mode depends on the international environment.

Martin Wight, one of the main theorists of IR in the English tradition, has argued that there are three main IR paradigms (Wight 1991): Realism, Rationalism and Revolutionism (the 3 "Rs"). These are schools of thought in IR theory. They are also policies that political leaders decide to follow. From this perspective, IR paradigms Martin Wight, "The Three Rs" (Wight 1991 are both theoretical and practice-oriented. Other IR theorists have provided typologies or IR theories (usually IR theory is divided into realism, liberalism and constructivism). 21 However, Wight's purpose is different, as these paradigms are both theoretical and practical and they are the constitutive elements of a dialectic as it shows in the following graph.

Wight, as well as other theorists such as Snyder, argues that state leaders' behavior is the reflection of IR paradigms. As echoes of IR explanatory models, ideas have therefore an impact on normative choices. We may add that those choices are also dependent upon internationally accepted set of norms, i.e., states can adopt a Realpolitik framework if there is, at least minimally, a shared set of beliefs about the validity of Realism. Such was the case during the Cold War during which both the US and the USSR agreed on "balance of power" as an international regulatory norm (as a shared set of expected behavior).

I argue the National interest and Global justice are compatible in some specific historical contexts. Depending on favorable windows of opportunity, a balance between the national interest and global justice can be found in the foreign policy of those states that have the capabilities to act according to those two lines and whose values are, at least partially, in accordance with those two world visions. Wight's graph shows that "soft" rationalism is close to "moderate" realism" and that "extreme" rationalism is close to "soft" revolutionism. These are the two areas where national interests and global justice could be compatible. In the context of détente during the Cold War, the US could combine its pursue of the national interest with international justice claims (moderate realism and soft rationalism). 22 The move from the international to the global mostly accelerated during the 90s (when extreme rationalism touched soft revolutionism). During the 90s, the US was more able to play on its "soft power". In the context of unilateralism, there was much less consensus about the definition of US national interest than during the Cold War. In the Middle East, for example, the US tried to use its soft power and establish itself as a peace broker between the Israelis and the Palestinians while trying to advance its strategic interests in the region. The idea of global justice made also significant progress in different areas of world politics such as the environment. This evolution was also heavily supported by strong individualist claims in western democratic societies (Colonomos 2008).

Part 2 Section 2 The Harmony of National Interests: An Ideal

World?

Realists claim that the pursuit of national interest is a universal rule that is profitable to every state and has intrinsically a stabilizing function. States would understand that it is not in their interest to engage in conflict with other units that are more powerful. Therefore, the number of conflicts would be reduced. The underlying logic 21 See Walt (1998) and Snyder (2009). 22 Indeed, the notion of interest gave rise to international society of states (Kratochwil 1982, 25). The National Interest and Global Justice: Contradictory Terms,…

is state rationality and cost-benefit analysis. Of course, this theory has been challenged. States cannot necessarily assess and anticipate the costs and the benefits of their decisions. There are epistemic limitations to foreign policy making and to the assessment of the national interest. Moreover, stability ought not to be the sole category upon which our judgment relies when making claims about the nature of foreign policy. Normatively, if every state ought to behave according to the precepts of Realism and if states were able to process accurately the information they needed to predict the consequences of their actions, the world might be stable, yet it would not be just. Indeed, this system promotes hegemony and inequality. This reminds us of one of the most famous quotes from the Melian dialogue in The Peloponnesian War (Book V): "right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must".

Reciprocity

A priori, the pursuit of the national interest reinforces hegemony. Yet, would it be possible to take into account some principles of global justice when defining the national interest? Let us imagine a world where the pursuit of the national interest for each country depends upon the national interest of other countries. Every state would share this principle and this belief. It would serve as a well-institutionalized norm prevailing in international organizations to which states delegate a share of their power.

Normatively, liberals would argue in favor of this position while claiming that this is a possible world. Constructivists would also claim that this is a plausible construction of reality. Some realists, especially defensive realists or "optimistic" realists would also agree that this is a possible state of affairs for world politics.

Normatively, this system would rely upon reciprocity as a meta-norm and would combine consequentialism and virtue ethics. Reciprocity would be the guiding principle of a world of non-selfish states that, nonetheless, strive for their survival. Thus, temperance would prevail. 23 In this environment, the economic and political interests of one country are secured only to the extent where the interests of other nations are also taken into account. Let us take the example of migration and let us imagine two scenarios. In the first one, states integrate migrants who accrue their resources and send money to their country of origin. In turn, migrants participate to the development of their homeland. Eventually, as those countries develop, migration flows will diminish over time. In the second scenario, Western states are reluctant to integrate migrants over security concerns or, else, they claim they are not ready to accept the cultural and historical changes that their presence over time would entail. However, they want to help the countries where those potential migrants come from. Development aid spurs economic growth, and it also augments the soft power of the donor countries. These are two optimistic scenarios, i.e., virtuous circles, in an interdependent world. 23 My argument relies here upon the compatibility of the explanation of national interest policies from a rationalist perspective and consequentialism as a normative model. However, given the high degree of interdependence today prevailing in international politics, assessing one's national interest while taking into account the national interests of all the other countries is very difficult. This would also mean that every state would adjust its policies according to its estimate of the national interests of other countries. As a concept and a framework, the national interest is future-oriented; therefore, each state would have to assess the national interests of their peers, that should, and, in turn, each of them should integrate this prediction into their own calculus. This is a true challenge both politically and epistemically. This iteration process stands as one of the strongest limitations of predictions in a highly interdependent international system (Colonomos 2016).

Reciprocity should also prevail in the area of justice. Global justice claims in one country should also take into account the definition of global justice in other parts of the world. Through this other iterative process, we should look for a more consensual vision of global justice. To some extent, this should be the task of international organizations or other global forums. As for now, the results we have achieved are limited. However, international organizations have at their disposal a great number of indicators (Davis et al. 2012). Yet, there is clearly room for improvement, as these are mostly governance tools and do not encapsulate a universally shared comprehensive global justice vision (i.e., a "global" global justice). Let us take another example. Hostage taking has greatly developed in the last few years, notably in Africa and in the Middle East. This has raised questions about what should be a legitimate and fair response to hostage-takers' claims. States, such as the UK and to some extent the US, opt in favor of a non-negotiation policy and refuse to make any compromise with those who have abducted their citizens. Other states, such as Israel, make important concessions in order to free their citizens, including political concessions such as the liberation of prisoners. States pay sometimes ransoms or offer other material counterparts, and this has been the case in France, for example, or in other countries of continental Europe.

Those who are in favor of the non-concession policy argue that any compromise made to the abductors will accrue the likelihood of kidnapping in the future. It will therefore endanger the security of their country, possibly hurting its national interest. Those who accept to make compromises act in the name of justice and the principle according to which no one should suffer from undue violence (Colonomos 2017a).

The national security and national interest arguments fall short, as British or American citizens are still fall in the hands of hostage-takers (non-payment did not have any deterrent effect). Moreover, from a global justice perspective, it is unfair that only those hostages whose countries accept to engage in negotiations in order to free them should be saved.

In this case, global justice claims should orient state decisions. Human rights claims and cultural traditions where the freeing of a member of one's community is a duty could influence the definition of the national interest. 24 States could agree on a mutual interest that would be consistent with some of the rules of global justice and engage in negotiation with hostage-takers. Hostage taking would still be considered a The National Interest and Global Justice: Contradictory Terms,… crime, and it should be fought as such. It would be easier to do so while aggregating the resources of those states that stand against this practice and organize a multilateral response to hostage crises and fight those that benefit from this crime.

A Future "Global" Global Justice?

US-China relations are one of the most important issues of world politics today. IR scholars speculate about the possibility of conflict between the two countries, while others claim that cooperation is and will be the prevailing mode of relation between the two countries (Colonomos 2016, 87-92). This, of course, raises anxiety and Sino-American relations are mostly discussed from the perspective of power (Coker 2005; Alison 2017). We may ask a different question. The US has always wanted to combine the pursuit of its national interests and global justice claims. Whether this a universal phenomenon or relative to the current historical moment we live in, this appears as an important step for a powerful state that is becoming a superpower and then wants to maintain that status. 25 We may wonder if China will follow its path. Hence, how would the two dyads (US and China national interests, US and China claims about global justice) be part of the same world? During the Cold War, both the US and the USSR were able to influence the definition of the national interest of their allies. In the context of bipolarity, two visions of justice both national and international opposed each other. In the near future, in a further stage of international politics, what would the relation between the US and China be like? Will it be more cooperative? This is a possibility, as, on an ad hoc basis, interests and visions of justice could converge. A specific international environment could favor their co-existence. 26 This, of course, could happen in the context of a world state. However, although there are speculations about the possibility of such a world entity, our world has not reached that stage yet (Wendt 2003). This appears as a more plausible claim, as for today, in order for this normative shift to happen, leaders from the two counties would need to be convinced that reciprocity works and that "honesty pays". 27 Let us then imagine a reciprocity scenario. Both countries and their allies would understand that it is in their mutual interest to adjust their policies and they would also need to make concessions on their cultural specificities. Indeed, their definition of what is global justice should not hurt the definition of global justice of their counterparts.

If this rapprochement were to happen, there would be some substantial benefits. This could ease some security tensions. It could also reinforce international regimes in the field of economics or the environment.

However, some other consequences might be expected. The very idea of pluralism would be affected. Countries would need to significantly adapt their normative 26 See the previous section. 27 Moral and normative revolutions happen. See Appiah (2010). frameworks, and this would seriously impact their culture and values. This could provoke some important domestic tensions and provoke identity crises. This universalism would always be imperiled by the resurgence of populism or nationalism, and this situation would be a fertile ground for these political ideologies to flourish. Paradoxically, idealism would also be affected as this global universalist revolution would need to make concessions in order for a "low level" equilibrium to be found. This could hamper moral imagination and could be an impediment in the development of new norms. We may wonder if this rapprochement will not lead both to an instable political environment and a cultural impoverishment, and if, in the end, this universalism would be detrimental to the richness of diversity that has been the grounding stone upon which civilization has, socially and culturally, developed. These hypothetical consequences should be taken into account in any debate on the future of global justice.

Conclusion: Can We Find the Right Proportion When Reconciling

the National Interest and Global Justice?

I have explored in this paper the different facets of the national interest global justice nexus. I have highlighted the deep gap that exists between these two sets of ideas and the two frameworks. Indeed, I have analyzed the primary historical, ideological and logical reasons that explain this radical difference between the two. However, the paper has also shown, from another perspective, that, contextually, despite this difference, the national interest and global justice can be compatible, mainly because they are adaptive and because their dyadic relation is historically and politically contingent. Then, does the world become a better place when the stars of power and justice align? As I showed in the last section of the paper, the rapprochement between the national interest and global justice, their "reconciliation," might not necessarily be the solution to the major political and moral problems we face in global politics. We should be, at least, aware that that this reconciliation may also result in some negative consequences.

It is important, for us, to understand, in substance, what is a good combination of the national interest and global justice and the right equilibrium that should prevail in this dyadic relation. When and in what area(s) one prevails over the other? Which one of the two, the "logic of consequences" or the "logic of appropriateness" prevails and in what context? 28 This paper has tried to provide some answers to this question, although this issue deserves much further investigation. Those are questions of great importance when both power and norms are in processes of change.

Moreover, if global justice is "costly," should it be "proportionate" to the costs that its implementation would entail for states willing to make concessions on the 28 These two concepts come from IR constructivist theory. The National Interest and Global Justice: Contradictory Terms,…

pursuit of what they see as their national interest? [START_REF]identity crises and populism mentioned above are also to be considered as costs[END_REF] Finding the right measurement is extremely demanding, precisely because it is difficult to disentangle these two elements. [START_REF]Selling the Future-The Perils of Predicting Global Politics[END_REF] This is also extremely difficult because those two goods are non-commensurable. We would need to redefine both concepts and find a "covering value". Yet, measuring, within one area of policy making or in a specific international environment, the degree to which one of the two logics is more predominant than the other would make a significant contribution to the debate on world politics. It would precisely facilitate a critical discussion and encourage policy makers, experts and citizens to share their views. Indicators might be used as tools for this measurement. Epistemically and politically, this would be a real challenge.

Finding the right national interest global justice balance also presupposes that we make assumptions about a state of world affairs to come, i.e., predictions or forecasts. Both frameworks, the national interest and global justice, are claims about the future. Indeed, in order to capture the national interest as a concept, we need to understand what are the key factors for the survival of the state. Global justice is also oriented toward the future: As a set of norms, it wants to set a path toward a better world. Therefore, any reflection on this dyad should engage into future-oriented analysis. The future dimension of the national interest and global justice is one aspect that makes their comparison difficult. Although it has alluded to this problem (both frameworks are undetermined), this paper has not fully taken this challenge. As new powers emerge and introduce change in global politics, the task is all the more pressing.

Whether they can be of any use at all in a non-western context is also a legitimate question.

On moralism and the political, see also[START_REF] Williams | In the Beginning was the Deed-Realism, Moralism in Political Argument[END_REF].

According to Bismarck, states are able to understand the nature of their interests and "no leader will risk the survival of his country to obey international law". 3FL01 4FL01

This shift could happen if we expose the invalidity of the utilitarian based non-compromising model.

The National Interest and Global Justice: Contradictory Terms,… international relations, the ethics of war and political sociology. His recent books include: Selling the Future -The Perils of Predicting Global Politics (Hurst -Oxford University Press, 2016), The Gamble of War (Palgrave, 2013).