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Empiricism

In philosophy, empiricism is an epistemological view which holds that true knowledge or justification comes only or primarily from sensory experience and empirical evidence. It is one of several competing views within epistemology, along with rationalism and skepticism. Empiricists argue that empiricism is a more reliable method of finding the truth than purely using logical reasoning, because humans have cognitive biases and limitations which lead to errors of judgement. Empiricism emphasizes the central role of empirical evidence in the formation of ideas, rather than innate ideas or traditions. Empiricists may argue that traditions (or customs) arise due to relations of previous sensory experiences.

Historically, empiricism was associated with the "blank slate" concept (tabula rasa), according to which the human mind is "blank" at birth and develops its thoughts only through later experience.

Empiricism in the philosophy of science emphasizes evidence, especially as discovered in experiments. It is a fundamental part of the scientific method that all hypotheses and theories must be tested against observations of the natural world rather than resting solely on a priori reasoning, intuition, or revelation.

Empiricism, often used by natural scientists, believes that "knowledge is based on experience" and that "knowledge is tentative and probabilistic, subject to continued revision and falsification". Empirical research, including experiments and validated measurement tools, guides the scientific method.

Etymology
The English term empirical derives from the Ancient Greek word ἐμπειρία, empeiria, which is cognate with and translates to the Latin experientia, from which the words experience and experiment are derived.

Background
A central concept in science and the scientific method is that conclusions must be empirically based on the evidence of the senses. Both natural and social sciences use working hypotheses that are testable by observation and experiment. The term semi-empirical is sometimes used to describe theoretical methods that make use of basic axioms, established scientific laws, and previous experimental results to engage in reasoned model building and theoretical inquiry.

Philosophical empiricists hold no knowledge to be properly inferred or deduced unless it is derived from one's sense-based experience. In epistemology (theory of knowledge) empiricism is typically contrasted with rationalism, which holds that knowledge may be derived from reason independently of the senses, and in the philosophy of mind it is often contrasted with innatism, which holds that some knowledge and ideas are already present in the mind at birth. However, many Enlightenment rationalists and empiricists still made concessions to each other. For example, the empiricist John Locke admitted that some knowledge (e.g. knowledge of God's existence) could be arrived at through intuition and reasoning alone. Similarly, Robert Boyle, a prominent advocate of the experimental method, held that we also have innate ideas. At the same time, the main continental rationalists (Descartes, Spinoza, and Leibniz) were also advocates of the empirical "scientific method".

Early empiricism
Between 600 and 200 BCE, the Vaisheshika school of Hindu philosophy, founded by the ancient Indian philosopher Kanada, accepted perception and inference as the only two reliable sources of knowledge. This is enumerated in his work Vaiśeṣika Sūtra. The Charvaka school held similar beliefs, asserting that perception is the only reliable source of knowledge while inference obtains knowledge with uncertainty.

The earliest Western proto-empiricists were the empiric school of ancient Greek medical practitioners, founded in 330 BCE. Its members rejected the doctrines of the dogmatic school, preferring to rely on the observation of phantasiai (i.e., phenomena, the appearances). The Empiric school was closely allied with the Pyrrhonist school of philosophy, which made the philosophical case for their proto-empiricism.

The notion of tabula rasa ("clean slate" or "blank tablet") connotes a view of the mind as an originally blank or empty recorder (Locke used the words "white paper") on which experience leaves marks. This denies that humans have innate ideas. The notion dates back to Aristotle, c. 350 BC:

"What the mind (nous) thinks must be in it in the same sense as letters are on a tablet (grammateion) which bears no actual writing (grammenon); this is just what happens in the case of the mind. (Aristotle, On the Soul, 3.4.430a1)."

Aristotle's explanation of how this was possible was not strictly empiricist in a modern sense, but rather based on his theory of potentiality and actuality, and experience of sense perceptions still requires the help of the active nous. These notions contrasted with Platonic notions of the human mind as an entity that pre-existed somewhere in the heavens, before being sent down to join a body on Earth (see Plato's Phaedo and Apology, as well as others). Aristotle was considered to give a more important position to sense perception than Plato, and commentators in the Middle Ages summarized one of his positions as "nihil in intellectu nisi prius fuerit in sensu" (Latin for "nothing in the intellect without first being in the senses").

This idea was later developed in ancient philosophy by the Stoic school, from about 330 BCE. Stoic epistemology generally emphasizes that the mind starts blank, but acquires knowledge as the outside world is impressed upon it. The doxographer Aetius summarizes this view as "When a man is born, the Stoics say, he has the commanding part of his soul like a sheet of paper ready for writing upon."

Islamic Golden Age and Pre-Renaissance (5th to 15th centuries CE)
During the Middle Ages (from the 5th to the 15th century CE) Aristotle's theory of tabula rasa was developed by Islamic philosophers starting with Al Farabi (c. 872), developing into an elaborate theory by Avicenna (c.  980 – 1037 CE) and demonstrated as a thought experiment by Ibn Tufail. For Avicenna (Ibn Sina), for example, the tabula rasa is a pure potentiality that is actualized through education, and knowledge is attained through "empirical familiarity with objects in this world from which one abstracts universal concepts" developed through a "syllogistic method of reasoning in which observations lead to propositional statements which when compounded lead to further abstract concepts". The intellect itself develops from a material intellect (al-'aql al-hayulani), which is a potentiality "that can acquire knowledge to the active intellect (al-'aql al-fa'il), the state of the human intellect in conjunction with the perfect source of knowledge". So the immaterial "active intellect", separate from any individual person, is still essential for understanding to occur.

In the 12th century CE, the Andalusian Muslim philosopher and novelist Abu Bakr Ibn Tufail (known as "Abubacer" or "Ebu Tophail" in the West) included the theory of tabula rasa as a thought experiment in his Arabic philosophical novel, Hayy ibn Yaqdhan in which he depicted the development of the mind of a feral child "from a tabula rasa to that of an adult, in complete isolation from society" on a desert island, through experience alone. The Latin translation of his philosophical novel, entitled Philosophus Autodidactus, published by Edward Pococke the Younger in 1671, had an influence on John Locke's formulation of tabula rasa in An Essay Concerning Human Understanding.

A similar Islamic theological novel, Theologus Autodidactus, was written by the Arab theologian and physician Ibn al-Nafis in the 13th century. It also dealt with the theme of empiricism through the story of a feral child on a desert island, but departed from its predecessor by depicting the development of the protagonist's mind through contact with society rather than in isolation from society.

During the 13th century Thomas Aquinas adopted into scholasticism the Aristotelian position that the senses are essential to the mind. Bonaventure (1221–1274), one of Aquinas' strongest intellectual opponents, offered some of the strongest arguments in favour of the Platonic idea of the mind.

Renaissance Italy
In the late renaissance various writers began to question the medieval and classical understanding of knowledge acquisition in a more fundamental way. In political and historical writing Niccolò Machiavelli and his friend Francesco Guicciardini initiated a new realistic style of writing. Machiavelli in particular was scornful of writers on politics who judged everything in comparison to mental ideals and demanded that people should study the "effectual truth" instead. Their contemporary, Leonardo da Vinci (1452–1519) said, "If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings."

Significantly, an empirical metaphysical system was developed by the Italian philosopher Bernardino Telesio which had an enormous impact on the development of later Italian thinkers, including Telesio's students Antonio Persio and Sertorio Quattromani, his contemporaries Thomas Campanella and Giordano Bruno, and later British philosophers such as Francis Bacon, who regarded Telesio as "the first of the moderns". Telesio's influence can also be seen on the French philosophers René Descartes and Pierre Gassendi.

The decidedly anti-Aristotelian and anti-clerical music theorist Vincenzo Galilei (c. 1520 – 1591), father of Galileo and the inventor of monody, made use of the method in successfully solving musical problems, firstly, of tuning such as the relationship of pitch to string tension and mass in stringed instruments, and to volume of air in wind instruments; and secondly to composition, by his various suggestions to composers in his Dialogo della musica antica e moderna (Florence, 1581). The Italian word he used for "experiment" was esperimento. It is known that he was the essential pedagogical influence upon the young Galileo, his eldest son (cf. Coelho, ed. Music and Science in the Age of Galileo Galilei), arguably one of the most influential empiricists in history. Vincenzo, through his tuning research, found the underlying truth at the heart of the misunderstood myth of 'Pythagoras' hammers' (the square of the numbers concerned yielded those musical intervals, not the actual numbers, as believed), and through this and other discoveries that demonstrated the fallibility of traditional authorities, a radically empirical attitude developed, passed on to Galileo, which regarded "experience and demonstration" as the sine qua non of valid rational enquiry.

British empiricism
British empiricism, a retrospective characterization, emerged during the 17th century as an approach to early modern philosophy and modern science. Although both integral to this overarching transition, Francis Bacon, in England, first advocated for empiricism in 1620, whereas René Descartes, in France, laid the main groundwork upholding rationalism around 1640. (Bacon's natural philosophy was influenced by Italian philosopher Bernardino Telesio and by Swiss physician Paracelsus.) Contributing later in the 17th century, Thomas Hobbes and Baruch Spinoza are retrospectively identified likewise as an empiricist and a rationalist, respectively. In the Enlightenment of the late 17th century, John Locke in England, and in the 18th century, both George Berkeley in England and David Hume in Scotland, all became leading exponents of empiricism, hence the dominance of empiricism in British philosophy. The distinction between rationalism and empiricism was not formally made until Immanuel Kant, in Germany, around 1780, who sought to merge the two views.

In response to the early-to-mid-17th-century "continental rationalism", John Locke (1632–1704) proposed in An Essay Concerning Human Understanding (1689) a very influential view wherein the only knowledge humans can have is a posteriori, i.e., based upon experience. Locke is famously attributed with holding the proposition that the human mind is a tabula rasa, a "blank tablet", in Locke's words "white paper", on which the experiences derived from sense impressions as a person's life proceeds are written. There are two sources of our ideas: sensation and reflection. In both cases, a distinction is made between simple and complex ideas. The former are unanalysable, and are broken down into primary and secondary qualities. Primary qualities are essential for the object in question to be what it is. Without specific primary qualities, an object would not be what it is. For example, an apple is an apple because of the arrangement of its atomic structure. If an apple were structured differently, it would cease to be an apple. Secondary qualities are the sensory information we can perceive from its primary qualities. For example, an apple can be perceived in various colours, sizes, and textures but it is still identified as an apple. Therefore, its primary qualities dictate what the object essentially is, while its secondary qualities define its attributes. Complex ideas combine simple ones, and divide into substances, modes, and relations. According to Locke, our knowledge of things is a perception of ideas that are in accordance or discordance with each other, which is very different from the quest for certainty of Descartes.

A generation later, the Irish Anglican bishop George Berkeley (1685–1753) determined that Locke's view immediately opened a door that would lead to eventual atheism. In response to Locke, he put forth in his Treatise Concerning the Principles of Human Knowledge (1710) an important challenge to empiricism in which things only exist either as a result of their being perceived, or by virtue of the fact that they are an entity doing the perceiving. (For Berkeley, God fills in for humans by doing the perceiving whenever humans are not around to do it.) In his text Alciphron, Berkeley maintained that any order humans may see in nature is the language or handwriting of God. Berkeley's approach to empiricism would later come to be called subjective idealism.

Scottish philosopher David Hume (1711–1776) responded to Berkeley's criticisms of Locke, as well as other differences between early modern philosophers, and moved empiricism to a new level of skepticism. Hume argued in keeping with the empiricist view that all knowledge derives from sense experience, but he accepted that this has implications not normally acceptable to philosophers. He wrote for example, "Locke divides all arguments into demonstrative and probable. On this view, we must say that it is only probable that all men must die or that the sun will rise to-morrow, because neither of these can be demonstrated. But to conform our language more to common use, we ought to divide arguments into demonstrations, proofs, and probabilities—by ‘proofs’ meaning arguments from experience that leave no room for doubt or opposition." And,

"I believe the most general and most popular explication of this matter, is to say [See Mr. Locke, chapter of power.], that finding from experience, that there are several new productions in matter, such as the motions and variations of body, and concluding that there must somewhere be a power capable of producing them, we arrive at last by this reasoning at the idea of power and efficacy. But to be convinced that this explication is more popular than philosophical, we need but reflect on two very obvious principles. First, That reason alone can never give rise to any original idea, and secondly, that reason, as distinguished from experience, can never make us conclude, that a cause or productive quality is absolutely requisite to every beginning of existence. Both these considerations have been sufficiently explained: and therefore shall not at present be any farther insisted on."

- Hume, Section XIV, "Of the idea of necessary connexion", in A Treatise of Human Nature

Hume divided all of human knowledge into two categories: relations of ideas and matters of fact (see also Kant's analytic-synthetic distinction). Mathematical and logical propositions (e.g. "that the square of the hypotenuse is equal to the sum of the squares of the two sides") are examples of the first, while propositions involving some contingent observation of the world (e.g. "the sun rises in the East") are examples of the second. All of people's "ideas", in turn, are derived from their "impressions". For Hume, an "impression" corresponds roughly with what we call a sensation. To remember or to imagine such impressions is to have an "idea". Ideas are therefore the faint copies of sensations.

Hume maintained that no knowledge, even the most basic beliefs about the natural world, can be conclusively established by reason. Rather, he maintained, our beliefs are more a result of accumulated habits, developed in response to accumulated sense experiences. Among his many arguments Hume also added another important slant to the debate about scientific method—that of the problem of induction. Hume argued that it requires inductive reasoning to arrive at the premises for the principle of inductive reasoning, and therefore the justification for inductive reasoning is a circular argument. Among Hume's conclusions regarding the problem of induction is that there is no certainty that the future will resemble the past. Thus, as a simple instance posed by Hume, we cannot know with certainty by inductive reasoning that the sun will continue to rise in the East, but instead come to expect it to do so because it has repeatedly done so in the past.

Hume concluded that such things as belief in an external world and belief in the existence of the self were not rationally justifiable. According to Hume these beliefs were to be accepted nonetheless because of their profound basis in instinct and custom. Hume's lasting legacy, however, was the doubt that his skeptical arguments cast on the legitimacy of inductive reasoning, allowing many skeptics who followed to cast similar doubt.

Phenomenalism
Most of Hume's followers have disagreed with his conclusion that belief in an external world is rationally unjustifiable, contending that Hume's own principles implicitly contained the rational justification for such a belief, that is, beyond being content to let the issue rest on human instinct, custom and habit. According to an extreme empiricist theory known as phenomenalism, anticipated by the arguments of both Hume and George Berkeley, a physical object is a kind of construction out of our experiences. Phenomenalism is the view that physical objects, properties, events (whatever is physical) are reducible to mental objects, properties, events. Ultimately, only mental objects, properties, events, exist—hence the closely related term subjective idealism. By the phenomenalistic line of thinking, to have a visual experience of a real physical thing is to have an experience of a certain kind of group of experiences. This type of set of experiences possesses a constancy and coherence that is lacking in the set of experiences of which hallucinations, for example, are a part. As John Stuart Mill put it in the mid-19th century, matter is the "permanent possibility of sensation". Mill's empiricism went a significant step beyond Hume in still another respect: in maintaining that induction is necessary for all meaningful knowledge including mathematics. As summarized by D.W. Hamlin:

"[Mill] claimed that mathematical truths were merely very highly confirmed generalizations from experience; mathematical inference, generally conceived as deductive [and a priori] in nature, Mill set down as founded on induction. Thus, in Mill's philosophy there was no real place for knowledge based on relations of ideas. In his view logical and mathematical necessity is psychological; we are merely unable to conceive any other possibilities than those that logical and mathematical propositions assert. This is perhaps the most extreme version of empiricism known, but it has not found many defenders."

Mill's empiricism thus held that knowledge of any kind is not from direct experience but an inductive inference from direct experience. The problems other philosophers have had with Mill's position center around the following issues: Firstly, Mill's formulation encounters difficulty when it describes what direct experience is by differentiating only between actual and possible sensations. This misses some key discussion concerning conditions under which such "groups of permanent possibilities of sensation" might exist in the first place. Berkeley put God in that gap; the phenomenalists, including Mill, essentially left the question unanswered. In the end, lacking an acknowledgement of an aspect of "reality" that goes beyond mere "possibilities of sensation", such a position leads to a version of subjective idealism. Questions of how floor beams continue to support a floor while unobserved, how trees continue to grow while unobserved and untouched by human hands, etc., remain unanswered, and perhaps unanswerable in these terms. Secondly, Mill's formulation leaves open the unsettling possibility that the "gap-filling entities are purely possibilities and not actualities at all". Thirdly, Mill's position, by calling mathematics merely another species of inductive inference, misapprehends mathematics. It fails to fully consider the structure and method of mathematical science, the products of which are arrived at through an internally consistent deductive set of procedures which do not, either today or at the time Mill wrote, fall under the agreed meaning of induction.

The phenomenalist phase of post-Humean empiricism ended by the 1940s, for by that time it had become obvious that statements about physical things could not be translated into statements about actual and possible sense data. If a physical object statement is to be translatable into a sense-data statement, the former must be at least deducible from the latter. But it came to be realized that there is no finite set of statements about actual and possible sense-data from which we can deduce even a single physical-object statement. The translating or paraphrasing statement must be couched in terms of normal observers in normal conditions of observation. There is, however, no finite set of statements that are couched in purely sensory terms and can express the satisfaction of the condition of the presence of a normal observer. According to phenomenalism, to say that a normal observer is present is to make the hypothetical statement that were a doctor to inspect the observer, the observer would appear to the doctor to be normal. But, of course, the doctor himself must be a normal observer. If we are to specify this doctor's normality in sensory terms, we must make reference to a second doctor who, when inspecting the sense organs of the first doctor, would himself have to have the sense data a normal observer has when inspecting the sense organs of a subject who is a normal observer. And if we are to specify in sensory terms that the second doctor is a normal observer, we must refer to a third doctor, and so on (also see the third man).

Logical empiricism
Logical empiricism (also logical positivism or neopositivism) was an early 20th-century attempt to synthesize the essential ideas of British empiricism (e.g. a strong emphasis on sensory experience as the basis for knowledge) with certain insights from mathematical logic that had been developed by Gottlob Frege and Ludwig Wittgenstein. Some of the key figures in this movement were Otto Neurath, Moritz Schlick and the rest of the Vienna Circle, along with A. J. Ayer, Rudolf Carnap and Hans Reichenbach.

The neopositivists subscribed to a notion of philosophy as the conceptual clarification of the methods, insights and discoveries of the sciences. They saw in the logical symbolism elaborated by Frege (1848–1925) and Bertrand Russell (1872–1970) a powerful instrument that could rationally reconstruct all scientific discourse into an ideal, logically perfect, language that would be free of the ambiguities and deformations of natural language. This gave rise to what they saw as metaphysical pseudoproblems and other conceptual confusions. By combining Frege's thesis that all mathematical truths are logical with the early Wittgenstein's idea that all logical truths are mere linguistic tautologies, they arrived at a twofold classification of all propositions: the "analytic" (a priori) and the "synthetic" (a posteriori). On this basis, they formulated a strong principle of demarcation between sentences that have sense and those that do not: the so-called "verification principle". Any sentence that is not purely logical, or is unverifiable, is devoid of meaning. As a result, most metaphysical, ethical, aesthetic and other traditional philosophical problems came to be considered pseudoproblems.

In the extreme empiricism of the neopositivists—at least before the 1930s—any genuinely synthetic assertion must be reducible to an ultimate assertion (or set of ultimate assertions) that expresses direct observations or perceptions. In later years, Carnap and Neurath abandoned this sort of phenomenalism in favor of a rational reconstruction of knowledge into the language of an objective spatio-temporal physics. That is, instead of translating sentences about physical objects into sense-data, such sentences were to be translated into so-called protocol sentences, for example, "X at location Y and at time T observes such and such". The central theses of logical positivism (verificationism, the analytic–synthetic distinction, reductionism, etc.) came under sharp attack after World War II by thinkers such as Nelson Goodman, W. V. Quine, Hilary Putnam, Karl Popper, and Richard Rorty. By the late 1960s, it had become evident to most philosophers that the movement had pretty much run its course, though its influence is still significant among contemporary analytic philosophers such as Michael Dummett and other anti-realists.

Pragmatism
In the late 19th and early 20th century, several forms of pragmatic philosophy arose. The ideas of pragmatism, in its various forms, developed mainly from discussions between Charles Sanders Peirce and William James when both men were at Harvard in the 1870s. James popularized the term "pragmatism", giving Peirce full credit for its patrimony, but Peirce later demurred from the tangents that the movement was taking, and redubbed what he regarded as the original idea with the name of "pragmaticism". Along with its pragmatic theory of truth, this perspective integrates the basic insights of empirical (experience-based) and rational (concept-based) thinking.

Charles Peirce (1839–1914) was highly influential in laying the groundwork for today's empirical scientific method. Although Peirce severely criticized many elements of Descartes' peculiar brand of rationalism, he did not reject rationalism outright. Indeed, he concurred with the main ideas of rationalism, most importantly the idea that rational concepts can be meaningful and the idea that rational concepts necessarily go beyond the data given by empirical observation. In later years he even emphasized the concept-driven side of the then ongoing debate between strict empiricism and strict rationalism, in part to counterbalance the excesses to which some of his cohorts had taken pragmatism under the "data-driven" strict-empiricist view.

Among Peirce's major contributions was to place inductive reasoning and deductive reasoning in a complementary rather than competitive mode, the latter of which had been the primary trend among the educated since David Hume wrote a century before. To this, Peirce added the concept of abductive reasoning. The combined three forms of reasoning serve as a primary conceptual foundation for the empirically based scientific method today. Peirce's approach "presupposes that (1) the objects of knowledge are real things, (2) the characters (properties) of real things do not depend on our perceptions of them, and (3) everyone who has sufficient experience of real things will agree on the truth about them. According to Peirce's doctrine of fallibilism, the conclusions of science are always tentative. The rationality of the scientific method does not depend on the certainty of its conclusions, but on its self-corrective character: by continued application of the method science can detect and correct its own mistakes, and thus eventually lead to the discovery of truth".

In his Harvard "Lectures on Pragmatism" (1903), Peirce enumerated what he called the "three cotary propositions of pragmatism" (L: cos, cotis whetstone), saying that they "put the edge on the maxim of pragmatism". First among these, he listed the peripatetic-thomist observation mentioned above, but he further observed that this link between sensory perception and intellectual conception is a two-way street. That is, it can be taken to say that whatever we find in the intellect is also incipiently in the senses. Hence, if theories are theory-laden then so are the senses, and perception itself can be seen as a species of abductive inference, its difference being that it is beyond control and hence beyond critique—in a word, incorrigible. This in no way conflicts with the fallibility and revisability of scientific concepts, since it is only the immediate percept in its unique individuality or "thisness"—what the Scholastics called its haecceity—that stands beyond control and correction. Scientific concepts, on the other hand, are general in nature, and transient sensations do in another sense find correction within them. This notion of perception as abduction has received periodic revivals in artificial intelligence and cognitive science research, most recently for instance with the work of Irvin Rock on indirect perception.

Around the beginning of the 20th century, William James (1842–1910) coined the term "radical empiricism" to describe an offshoot of his form of pragmatism, which he argued could be dealt with separately from his pragmatism—though in fact the two concepts are intertwined in James's published lectures. James maintained that the empirically observed "directly apprehended universe needs ... no extraneous trans-empirical connective support", by which he meant to rule out the perception that there can be any value added by seeking supernatural explanations for natural phenomena. James' "radical empiricism" is thus not radical in the context of the term "empiricism", but is instead fairly consistent with the modern use of the term "empirical". His method of argument in arriving at this view, however, still readily encounters debate within philosophy even today.

John Dewey (1859–1952) modified James' pragmatism to form a theory known as instrumentalism. The role of sense experience in Dewey's theory is crucial, in that he saw experience as unified totality of things through which everything else is interrelated. Dewey's basic thought, in accordance with empiricism, was that reality is determined by past experience. Therefore, humans adapt their past experiences of things to perform experiments upon and test the pragmatic values of such experience. The value of such experience is measured experientially and scientifically, and the results of such tests generate ideas that serve as instruments for future experimentation, in physical sciences as in ethics. Thus, ideas in Dewey's system retain their empiricist flavour in that they are only known a posteriori.

title: Empiricism


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Estampie

The estampie (estampie, Occitan and estampida, istanpitta) is a medieval dance and musical form which was a popular instrumental and vocal form in the 13th and 14th centuries. The name was also applied to poetry.

Musical form
The estampie is similar in form to the lai, consisting of a succession of repeated notes. According to Johannes de Grocheio, there were both vocal and instrumental estampies (for which he used the Latin calque "stantipes"), which differed somewhat in form.

Grocheio calls the sections in both the French vocal and instrumental estampie puncta (singular punctus), Each puncta has a pair of lines that repeat the same melody, in the form:

 * aa, bb, cc, etc..

The two statements of the melody in each punctus differ only in their endings, described as apertum ("open") and clausum ("closed") by Grocheio, who believed that six puncta were standard for the stantipes (his term for the estampie), though he was aware of stantipes with seven puncta. The structure can therefore be diagrammed as:

 * a+x, a+y; b+w, b+z; etc..

In an instrumental estampie, the open and closed endings of the puncta are the same each time, so that the end of the punctum serves as the refrain, in the form:

a+x, a+y; b+x, b+y, c+x, c+y, etc.

In comparison to other dance forms, Grocheio considered the instrumental estampie "complicated," with puncta of varying lengths This is in contrast to the more regular verse length of the ductia. There are also more puncta in an estampie than in a ductia. He further states that this difficulty captivates the attention of both the players and listeners because of these complications. According to Grocheio, the vocal estampie begins with a refrain, which is repeated at the end of each stanza, with text and melody independent of the stanza. However, surviving songs do not include a section labeled as a refrain, so some scholars suggest that a convention must have existed for choosing lines to use as a refrain. Like the instrumental form, the vocal dance was complicated enough to require concentration, which helps to distract young people from wicked thoughts.

History
The estampie is the first known genre of medieval era dance music which continues to exist today. The earliest reported example of this musical form is the song "Kalenda maya", written by the troubadour Raimbaut de Vaqueiras (1180–1207), possibly to a preexisting melody. 14th century examples include estampies with subtitles such as "Isabella" and "Tre fontane".

Instrumentation
Sources for individual songs do not generally indicate what instruments were used. However, according to Grocheio, the vielle was the supreme instrument of the period, and the stantipes, together with the cantus coronatus and ductia, were the principal forms played on vielles before the wealthy in their celebration. Though the estampie is generally monophonic, there are also two-voice compositions in the form of an estampie, such as the two for keyboard in the Robertsbridge Fragment. The French estampie was performed in a lively triple meter, a primary division of three beats to the bar.

Etymology
According to the OED, the name comes from the Provençal estampida, feminine of estampit, the past participle of estampir "to resound".

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Estampie


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Experimental cancer treatment

Experimental cancer treatments are mainstream medical therapies intended to treat cancer by improving on, supplementing or replacing conventional methods (surgery, chemotherapy, radiation, and immunotherapy). However, researchers are still trying to determine whether these treatments are safe and effective treatments. Experimental cancer treatments are normally available only to people who participate in formal research programs, which are called clinical trials. Occasionally, a seriously ill person may be able to access an experimental drug through an expanded access program. Some of the treatments have regulatory approval for treating other conditions. Health insurance and publicly funded health care programs normally refuse to pay for experimental cancer treatments.

The entries listed below vary between theoretical therapies to unproven controversial therapies. Many of these treatments are alleged to help against only specific forms of cancer. It is not a list of treatments widely available at hospitals.

Studying treatments for cancer
The twin goals of research are to determine whether the treatment actually works (called efficacy) and whether it is sufficiently safe. Regulatory processes attempt to balance the potential benefits with the potential harms, so that people given the treatment are more likely to benefit from it than to be harmed by it.

Medical research for cancer begins much like research for any disease. In organized studies of new treatments for cancer, the pre-clinical development of drugs, devices, and techniques begins in laboratories, either with isolated cells or in small animals, most commonly rats or mice. In other cases, the proposed treatment for cancer is already in use for some other medical condition, in which case more is known about its safety and potential efficacy.

Clinical trials are the study of treatments in humans. The first-in-human tests of a potential treatment are called Phase I studies. Early clinical trials typically enroll a very small number of patients, and the purpose is to identify major safety issues and the maximum tolerated dose, which is the highest dose that does not produce serious or fatal adverse effects. The dose given in these trials may be far too small to produce any useful effect. In most research, these early trials may involve healthy people, but cancer studies normally enroll only people with relatively severe forms of the disease in this stage of testing. On average, 95% of the participants in these early trials receive no benefit, but all are exposed to the risk of adverse effects. Most participants show signs of optimism bias (the irrational belief that they will beat the odds).

Later studies, called Phase II and Phase III studies, enroll more people, and the goal is to determine whether the treatment actually works. Phase III studies are frequently randomized controlled trials, with the experimental treatment being compared to the current best available treatment rather than to a placebo. In some cases, the Phase III trial provides the best available treatment to all participants, in addition to some of the patients receiving the experimental treatment.

Bacterial treatments
Chemotherapeutic drugs have a hard time penetrating tumors to kill them at their core because these cells may lack a good blood supply. Researchers have been using anaerobic bacteria, such as Clostridium novyi, to consume the interior of oxygen-poor tumours. These should then die when they come in contact with the tumor's oxygenated sides, meaning they would be harmless to the rest of the body. A major problem has been that bacteria do not consume all parts of the malignant tissue. However, combining the therapy with chemotherapeutic treatments can help to solve this problem.

Another strategy is to use anaerobic bacteria that have been transformed with an enzyme that can convert a non-toxic prodrug into a toxic drug. With the proliferation of the bacteria in the necrotic and hypoxic areas of the tumor, the enzyme is expressed solely in the tumor. Thus, a systemically applied prodrug is metabolised to the toxic drug only in the tumor. This has been demonstrated to be effective with the nonpathogenic anaerobe Clostridium sporogenes.

HAMLET (human alpha-lactalbumin made lethal to tumor cells)
HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a molecular complex derived from human breast milk that kills tumor cells by a process resembling programmed cell death (apoptosis). , it had been tested in humans with skin papillomas and bladder cancer.

p53 activation therapy
Several drug therapies are being developed based on p53, the tumour suppressor gene that protects the cell in response to damage and stress. It is analogous to deciding what to do with a damaged car: p53 brings everything to a halt, and then decides whether to fix the cell or, if the cell is beyond repair, to destroy the cell. This protective function of p53 is disabled in most cancer cells, allowing them to multiply without check. Restoration of p53 activity in tumours (where possible) has been shown to inhibit tumour growth and can even shrink the tumour.

As p53 protein levels are usually kept low, one could block its degradation and allow large amounts of p53 to accumulate, thus stimulating p53 activity and its antitumour effects. Drugs that utilize this mechanism include nutlin and MI-219, which are both in phase I clinical trials. , there are also other drugs that are still in the preclinical stage of testing, such as RITA and MITA.

BI811283
BI811283 is a small molecule inhibitor of the aurora B kinase protein being developed by Boehringer Ingelheim for use as an anti-cancer agent. , BI 811283 is currently in the early stages of clinical development and is undergoing first-in-human trials in patients with solid tumors and Acute Myeloid Leukaemia.

Itraconazole
Itraconazole, sometimes abbreviated ITZ, is an antifungal medication used to treat a number of fungal infections. Recent research works suggest itraconazole (ITZ) could also be used in the treatment of cancer by inhibiting the hedgehog pathway in a similar way to Sonidegib.

Selective androgen receptor modulators
The majority of breast cancers are androgen receptor (AR) positive and SARMs may help treat these cancers, although promising results have only been obtained with cancers that are both estrogen receptor (ER) positive and AR positive. Anabolic androgenic steroids (AAS) were historically used successfully to treat AR positive breast cancer, but were phased out after the development of anti-estrogen therapies, due to androgenic side effects and concerns about aromatization to estrogen. SARMs have some of the same therapeutic effects as AAS, but fewer side effects, and they cannot be aromatized. Although a trial on AR positive triple negative breast cancer was ended early due to lack of efficacy, ostarine showed benefits in some patients with ER+, AR+ metastatic breast cancer in a phase II study. In patients with more than 40 percent AR positivity as determined by immunohistochemistry, the clinical benefit rate (CBR) was 80 percent and the objective response rate (ORR) was 48 percent—which was considered promising given that the patients had advanced disease and had been heavily pretreated. In 2022, the FDA granted fast track designation to ostarine for AR+, ER+, HER2- metastatic breast cancer. SARMs have also shown antitumor effects in prostate cancer.

Gene therapy
Introduction of tumor suppressor genes into rapidly dividing cells has been thought to slow down or arrest tumor growth. Adenoviruses are a commonly utilized vector for this purpose. Much research has focused on the use of adenoviruses that cannot reproduce, or reproduce only to a limited extent, within the patient to ensure safety via the avoidance of cytolytic destruction of noncancerous cells infected with the vector. However, new studies focus on adenoviruses that can be permitted to reproduce, and destroy cancerous cells in the process, since the adenoviruses' ability to infect normal cells is substantially impaired, potentially resulting in a far more effective treatment.

Another use of gene therapy is the introduction of enzymes into these cells that make them susceptible to particular chemotherapy agents; studies with introducing thymidine kinase in gliomas, making them susceptible to aciclovir, are in their experimental stage.

Epigenetic options
Epigenetics is the study of heritable changes in gene activity that are not caused by changes in the DNA sequence, often a result of environmental or dietary damage to the histone receptors within the cell. Current research has shown that epigenetic pharmaceuticals could be a putative replacement or adjuvant therapy for currently accepted treatment methods such as radiation and chemotherapy, or could enhance the effects of these current treatments. It has been shown that the epigenetic control of the proto-onco regions and the tumor suppressor sequences by conformational changes in histones directly affects the formation and progression of cancer. Epigenetics also has the factor of reversibility, a characteristic that other cancer treatments do not offer.

Some investigators, like Randy Jirtle, PhD, of Duke University Medical Center, think epigenetics may ultimately turn out to have a greater role in disease than genetics.

Telomerase deactivation therapy
Because most malignant cells rely on the activity of the protein telomerase for their immortality, it has been proposed that a drug that inactivates telomerase might be effective against a broad spectrum of malignancies. At the same time, most healthy tissues in the body express little if any telomerase, and would function normally in its absence. Currently, inositol hexaphosphate, which is available over-the-counter, is undergoing testing in cancer research due to its telomerase-inhibiting abilities.

A number of research groups have experimented with the use of telomerase inhibitors in animal models, and as of 2005 and 2006 phase I and II human clinical trials are underway. Geron Corporation is currently conducting two clinical trials involving telomerase inhibitors. One uses a vaccine (GRNVAC1) and the other uses a lipidated oligonucleotide (GRN163L).

Photodynamic therapy
Photodynamic therapy (PDT) is generally a non-invasive treatment using a combination of light and a photosensitive drug, such as 5-ALA, Foscan, Metvix, padeliporfin (Tookad, WST09, WST11), Photofrin, or Visudyne. The drug is triggered by light of a specific wavelength.

Hyperthermiatic therapy
Localized and whole-body application of heat has been proposed as a technique for the treatment of malignant tumours. Intense heating will cause denaturation and coagulation of cellular proteins, rapidly killing cells within a tumour.

More prolonged moderate heating to temperatures just a few degrees above normal (39.5 °C) can cause more subtle changes. A mild heat treatment combined with other stresses can cause cell death by apoptosis. There are many biochemical consequences to the heat shock response within the cell, including slowed cell division and increased sensitivity to ionizing radiation therapy. The purpose of overheating the tumor cells is to create a lack of oxygen so that the heated cells become overacidified, which leads to a lack of nutrients in the tumor. This in turn disrupts the metabolism of the cells so that cell death (apoptosis) can set in. In certain cases chemotherapy or radiation that has previously not had any effect can be made effective. Hyperthermia alters the cell walls by means of so-called heat shock proteins. The cancer cells then react very much more effectively to the cytostatics and radiation. If hyperthermia is used conscientiously it has no serious side effects.

There are many techniques by which heat may be delivered. Some of the most common involve the use of focused ultrasound (FUS or HIFU), microwave heating, induction heating, magnetic hyperthermia, and direct application of heat through the use of heated saline pumped through catheters. Experiments with carbon nanotubes that selectively bind to cancer cells have been performed. Lasers are then used that pass harmlessly through the body, but heat the nanotubes, causing the death of the cancer cells. Similar results have also been achieved with other types of nanoparticles, including gold-coated nanoshells and nanorods that exhibit certain degrees of 'tunability' of the absorption properties of the nanoparticles to the wavelength of light for irradiation. The success of this approach to cancer treatment rests on the existence of an 'optical window' in which biological tissue (i.e., healthy cells) are completely transparent at the wavelength of the laser light, while nanoparticles are highly absorbing at the same wavelength. Such a 'window' exists in the so-called near-infrared region of the electromagnetic spectrum. In this way, the laser light can pass through the system without harming healthy tissue, and only diseased cells, where the nanoparticles reside, get hot and are killed.

Magnetic Hyperthermia makes use of magnetic nanoparticles, which can be injected into tumours and then generate heat when subjected to an alternating magnetic field.

One of the challenges in thermal therapy is delivering the appropriate amount of heat to the correct part of the patient's body. A great deal of current research focuses on precisely positioning heat delivery devices (catheters, microwave, and ultrasound applicators, etc.) using ultrasound or magnetic resonance imaging, as well as of developing new types of nanoparticles that make them particularly efficient absorbers while offering little or no concerns about toxicity to the circulation system. Clinicians also hope to use advanced imaging techniques to monitor heat treatments in real time—heat-induced changes in tissue are sometimes perceptible using these imaging instruments. In magnetic hyperthermia or magnetic fluid hyperthermia method, it will be easier to control temperature distribution by controlling the velocity of ferrofluid injection and size of magnetic nanoparticles.

Noninvasive cancer heat treatment
Heat treatment involves using radio waves to heat up tiny metals that are implanted in cancerous tissue. Gold nanoparticles or carbon nanotubes are the most likely candidate. Promising preclinical trials have been conducted, although clinical trials may not be held for another few years.

Another method that is entirely non-invasive referred to as Tumor Treating Fields has already reached clinical trial stage in many countries. The concept applies an electric field through a tumour region using electrodes external to the body. Successful trials have shown the process effectiveness to be greater than chemotherapy and there are no side-effects and only negligible time spent away from normal daily activities. This treatment is still in very early development stages for many types of cancer.

High-intensity focused ultrasound (HIFU) is still in investigatory phases in many places around the world. In China it has CFDA approval and over 180 treatment centres have been established in China, Hong Kong, and Korea. HIFU has been successfully used to treat cancer to destroy tumours of the bone, brain, breast, liver, pancreas, rectum, kidney, testes, and prostate. Several thousand patients have been treated with various types of tumours. HIFU has CE approval for palliative care for bone metastasis. Experimentally, palliative care has been provided for cases of advanced pancreatic cancer. High-energy therapeutic ultrasound could increase higher-density anti-cancer drug load and nanomedicines to target tumor sites by 20x fold higher than traditional target cancer therapy.

Cold atmospheric plasma treatment
Cold atmospheric plasma or CAP for short is an emerging modality for the treatment of solid tumors Recently, cold atmospheric plasma (CAP) indicated promising anti-neoplastic effects on several tumors, e.g. melanoma, glioma, and pancreatic cancer cells [5, 6, 7], and therefore could be an efficient method for anti-cancer treatment in clinical urology in the future. One example of an experimental technology utilizing Cold Atmospheric plasma is Theraphi

Electromagnetic treatments
Tumor Treating Fields is a novel FDA-approved cancer treatment therapy that uses alternating electric field to disturb the rapid cell division exhibited by cancer cells.

Complementary and alternative treatments
Complementary and alternative medicine (CAM) treatments are the diverse group of medical and healthcare systems, practices, and products that are not part of conventional medicine and have not been proven to be effective. Complementary medicine usually refers to methods and substances used along with conventional medicine, while alternative medicine refers to compounds used instead of conventional medicine. CAM use is common among people with cancer.

Most complementary and alternative medicines for cancer have not been rigorously studied or tested. Some alternative treatments that have been proven ineffective continue to be marketed and promoted.

title: Experimental cancer treatment


text:
Emission

Emission may refer to:

Chemical products

 * Emission of air pollutants, notably:
 * Flue gas, gas exiting to the atmosphere via a flue
 * Exhaust gas, flue gas generated by fuel combustion
 * Emission of greenhouse gases, which absorb and emit radiant energy within the thermal infrared range
 * Emission standards, limits on pollutants that can be released into the environment
 * Emissions trading, a market-based approach to pollution control

Electromagnetic radiation

 * Emission spectrum, the spectrum of frequencies of electromagnetic radiation generated by molecular electrons making transitions to lower energy states
 * Thermal emission, electromagnetic radiation generated by the thermal motion of particles in matter
 * List of light sources, including both natural and artificial processes that emit light
 * Emission (radiocommunications), a radio signal (usually modulated) emitted from a radio transmitter
 * Emission coefficient, a coefficient in the power output per unit time of an electromagnetic source
 * Emission line, or "spectral line", a dark or bright line in an otherwise uniform and continuous spectrum
 * Emission nebula, a cloud of ionized gas emitting light of various colors
 * Emission theory (relativity), a competing theory for the special theory of relativity, explaining the results of the Michelson-Morley experiment
 * Emission theory (vision), the proposal that visual perception is accomplished by rays of light emitted by the eyes

Other uses

 * Thermionic emission, the flow of charged particles called thermions from a charged metal or a charged metal oxide surface, archaically known as the Edison effect
 * Ejaculation, the ejection of semen from the penis; also, specifically:
 * Nocturnal emission, ejaculation experienced during sleep
 * Noise, emission
 * Exhalation of air, especially in the context of musical instruments

title: Emission


text:
Environmental movement in the United States

The organized environmental movement is represented by a wide range of non-governmental organizations or NGOs that seek to address environmental issues in the United States. They operate on local, national, and international scales. Environmental NGOs vary widely in political views and in the ways they seek to influence the environmental policy of the United States and other governments.

The environmental movement today consists of both large national groups and also many smaller local groups with local concerns. Some resemble the old U.S. conservation movement - whose modern expression is The Nature Conservancy, Audubon Society and National Geographic Society - American organizations with a worldwide influence. Increasingly that movement is organized around addressing climate change in the United States alongside interrelated issues like climate justice and broader environmental justice issues.

Scope of the movement
As public awareness and the environmental sciences have improved in recent years, environmental issues have broadened to include key concepts such as "sustainability" and also new emerging concerns such as ozone depletion, global warming, acid rain, land use and biogenetic pollution.
 * The early Conservation movement, which began in the late 19th century, included fisheries and wildlife management, water, soil conservation and sustainable forestry. Today it includes sustainable yield of natural resources, preservation of wilderness areas and biodiversity.
 * The modern Environmental movement, which began in the 1960s with concern about air and water pollution, became broader in scope to include all landscapes and human activities. See List of environmental issues.
 * Environmental health movement dating at least to Progressive Era (the 1890s - 1920s) urban reforms including clean water supply, more efficient removal of raw sewage and reduction in crowded and unsanitary living conditions. Today Environmental health is more related to nutrition, preventive medicine, ageing well and other concerns specific to the human body's well-being.
 * Sustainability movement which started in the 1980s focused on Gaia theory, value of Earth and other interrelations between human sciences and human responsibilities. Its spinoff deep ecology was more spiritual but often claimed to be science.

Environmental movements often interact or are linked with other social movements, e.g. for peace, human rights, and animal rights; and against nuclear weapons and/or nuclear power, endemic diseases, poverty, hunger, etc.

Some US colleges are now going green by signing the "President's Climate Commitment," a document that a college President can sign to enable said colleges to practice environmentalism by switching to solar power, etc.

History
Native Americans are frequently categorized as "the original environmentalists", however this assertion is frequently challenged for being overly simplistic. Early European settlers came to the United States brought from Europe the concept of the commons. In the colonial era, access to natural resources was allocated by individual towns, and disputes over fisheries or land use were resolved at the local level. Changing technologies, however, strained traditional ways of resolving disputes of resource use, and local governments had limited control over powerful special interests. For example, the damming of rivers for mills cut off upriver towns from fisheries; logging and clearing of forest in watersheds harmed local fisheries downstream. In New England, many farmers became uneasy as they noticed clearing of the forest changed stream flows and a decrease in bird population which helped control insects and other pests. These concerns become widely known with the publication of Man and Nature (1864) by George Perkins Marsh. The environmental impact method of analysis is generally the main mode for determining what issues the environmental movement is involved in. This model is used to determine how to proceed in situations that are detrimental to the environment by choosing the way that is least damaging and has the fewest lasting implications.

Conservation movement
Conservation first became a national issue during the progressive era's conservation movement (1890s - 1920s). The early national conservation movement shifted emphasis to scientific management which favored larger enterprises and control began to shift from local governments to the states and the federal government.(Judd) Some writers credit sportsmen, hunters and fishermen with the increasing influence of the conservation movement. In the 1870s sportsman magazines such as American Sportsmen, Forest and Stream, and Field and Stream are seen as leading to the growth of the conservation movement.(Reiger) This conservation movement also urged the establishment of state and national parks and forests, wildlife refuges, and national monuments intended to preserve noteworthy natural features. Conservation groups focus primarily on an issue that's origins are rooted in general expansion. As industrialization became more prominent as well as the increasing trend towards urbanization the conservative environmental movement began. Contrary to popular belief conservation groups are not against expansion in general, instead, they are concerned with efficiency with resources and land development.

Progressive era
Theodore Roosevelt and his close ally George Bird Grinnell, were motivated by the wanton waste that was taking place at the hand of market hunting. This practice resulted in placing a large number of North American game species on the edge of extinction. Roosevelt recognized that the laissez-faire approach of the U.S. Government was too wasteful and inefficient. In any case, they noted, most of the natural resources in the western states were already owned by the federal government. The best course of action, they argued, was a long-term plan devised by national experts to maximize the long-term economic benefits of natural resources. To accomplish the mission, Roosevelt and Grinnell formed the Boone and Crockett Club in 1887. The club was made up of the best minds and influential men of the day. The Boone and Crockett Club's contingency of conservationists, scientists, politicians, and intellectuals became Roosevelt's closest advisers during his march to preserve wildlife and habitat across North America. As president, Theodore Roosevelt became a prominent conservationist, putting the issue high on the national agenda. He worked with all the major figures of the movement, especially his chief advisor on the matter, Gifford Pinchot. Roosevelt was deeply committed to conserving natural resources and is considered to be the nation's first conservation President. He encouraged the Newlands Reclamation Act of 1902 to promote federal construction of dams to irrigate small farms and placed 230000000 acre under federal protection. Roosevelt set aside more Federal land for national parks and nature preserves than all of his predecessors combined.

Roosevelt established the United States Forest Service, signed into law the creation of five National Parks, and signed the 1906 Antiquities Act, under which he proclaimed 18 new U.S. National Monuments. He also established the first 51 Bird Reserves, four Game Preserves, and 150 National Forests, including Shoshone National Forest, the nation's first. The area of the United States that he placed under public protection totals approximately 230000000 acre.

Gifford Pinchot had been appointed by McKinley as chief of Division of Forestry in the Department of Agriculture. In 1905, his department gained control of the national forest reserves. Pinchot promoted private use (for a fee) under federal supervision. In 1907, Roosevelt designated 16 e6acre of new national forests just minutes before a deadline.

In May 1908, Roosevelt sponsored the Conference of Governors held in the White House, with a focus on natural resources and their most efficient use. Roosevelt delivered the opening address: "Conservation as a National Duty."

In 1903 Roosevelt toured the Yosemite Valley with John Muir, who had a very different view of conservation and tried to minimize commercial use of water resources and forests. Working through the Sierra Club he founded, Muir succeeded in 1905 in having Congress transfer the Mariposa Grove and Yosemite Valley to the National Park Service. While Muir wanted nature preserved for the sake of pure beauty, Roosevelt subscribed to Pinchot's formulation, "to make the forest produce the largest amount of whatever crop or service will be most useful, and keep on producing it for generation after generation of men and trees." Muir and the Sierra Club vehemently opposed the damming of the Hetch Hetchy Valley in Yosemite in order to provide water to the city of San Francisco. Roosevelt and Pinchot supported the dam, as did President Woodrow Wilson. The Hetch Hetchy dam was finished in 1923 and is still in operation, but the Sierra Club still wants to tear it down.

Other influential conservationists of the Progressive Era included George Bird Grinnell (a prominent sportsman who founded the Boone and Crockett Club), the Izaak Walton League and John Muir, the founder of the Sierra Club in 1892. Conservationists organized the National Parks Conservation Association, the Audubon Society, and other groups that still remain active.

New Deal
Franklin Delano Roosevelt (1933–45), like his cousin Theodore Roosevelt, was an ardent conservationist. He used numerous programs of the departments of Agriculture and Interior to end wasteful land-use, mitigate the effects of the Dust Bowl, and efficiently develop natural resources in the West. One of the most popular of all New Deal programs was the Civilian Conservation Corps (1933–1943), which sent two million poor young men to work in rural and wilderness areas, primarily on conservation projects.

Post-1945
After World War II increasing encroachment on wilderness land evoked the continued resistance of conservationists, who succeeded in blocking a number of projects in the 1950s and 1960s, including the proposed Bridge Canyon Dam that would have backed up the waters of the Colorado River into the Grand Canyon National Park.

The Inter-American Conference on the Conservation of Renewable Natural Resources met in 1948 as a collection of nearly 200 scientists from all over the Americans forming the trusteeship principle that:

"No generation can exclusively own the renewable resources by which it lives. We hold the commonwealth in trust for prosperity, and to lessen or destroy it is to commit treason against the future"

Beginning of the modern movement

During the 1950s, 1960s and 1970s, several events occurred which raised the public awareness of harm to the environment caused by man. In 1954, the 23 man crew of the Japanese fishing vessel Lucky Dragon was exposed to radioactive fallout from a hydrogen bomb test at Bikini Atoll. By 1969, the public reaction to an ecologically catastrophic oil spill from an offshore well in California's Santa Barbara Channel, Barry Commoner's protest against nuclear testing, along with Rachel Carson's 1962 book Silent Spring, and Paul R. Ehrlich's The Population Bomb (1968) all added anxiety about the environment. Pictures of Earth from space emphasized that the earth was small and fragile.

As the public became more aware of environmental issues, concern about air pollution, water pollution, solid waste disposal, dwindling energy resources, radiation, pesticide poisoning (particularly use of DDT as described in Carson's influential Silent Spring), noise pollution, and other environmental problems engaged a broadening number of sympathizers. That public support for environmental concerns was widespread became clear in the Earth Day demonstrations of 1970.

Several books after the middle of the 20th century contributed to the rise of American environmentalism (as distinct from the longer-established conservation movement), especially among college and university students and the more literate public. One was the publication of the first textbook on ecology, Fundamentals of Ecology, by Eugene Odum and Howard Odum, in 1953. Another was the appearance of the Carson's 1962 best-seller Silent Spring. Her book brought about a whole new interpretation of pesticides by exposing their harmful effects in nature. From this book, many began referring to Carson as the "mother of the environmental movement". Another influential development was a 1965 lawsuit, Scenic Hudson Preservation Conference v. Federal Power Commission, opposing the construction of a power plant on Storm King Mountain in New York (state), which is said to have given birth to modern United States environmental law. The wide popularity of The Whole Earth Catalogs, starting in 1968, was quite influential among the younger, hands-on, activist generation of the 1960s and 1970s. Recently, in addition to opposing environmental degradation and protecting wilderness, an increased focus on coexisting with natural biodiversity has appeared, a strain that is apparent in the movement for sustainable agriculture and in the concept of Reconciliation Ecology.

During his time as U.S President, Lyndon Johnson would sign over 300 environment protection measures into law. This was credited as forming the legal basis of the modern environmental movement.

Wilderness preservation
In the modern wilderness preservation movement, important philosophical roles are played by the writings of John Muir who had been activist in the late 19th and early 20th century. Along with Muir perhaps most influential in the modern movement is Henry David Thoreau who published Walden in 1854. Also important was forester and ecologist Aldo Leopold, one of the founders of the Wilderness Society in 1935, who wrote a classic of nature observation and ethical philosophy, A Sand County Almanac, (1949).

There is also a growing movement of campers and other people who enjoy outdoor recreation activities to help preserve the environment while spending time in the wilderness.

Anti-nuclear movement
The anti-nuclear movement in the United States consists of more than 80 anti-nuclear groups that have acted to oppose nuclear power or nuclear weapons, or both, in the United States. These groups include the Abalone Alliance, Clamshell Alliance, Institute for Energy and Environmental Research, Nuclear Information and Resource Service, and Physicians for Social Responsibility. The anti-nuclear movement has delayed construction or halted commitments to build some new nuclear plants, and has pressured the Nuclear Regulatory Commission to enforce and strengthen the safety regulations for nuclear power plants.

Anti-nuclear protests reached a peak in the 1970s and 1980s and grew out of the environmental movement. Campaigns which captured national public attention involved the Calvert Cliffs Nuclear Power Plant, Seabrook Station Nuclear Power Plant, Diablo Canyon Power Plant, Shoreham Nuclear Power Plant, and Three Mile Island. On June 12, 1982, one million people demonstrated in New York City's Central Park against nuclear weapons and for an end to the cold war arms race. It was the largest anti-nuclear protest and the largest political demonstration in American history. International Day of Nuclear Disarmament protests were held on June 20, 1983 at 50 sites across the United States. There were many Nevada Desert Experience protests and peace camps at the Nevada Test Site during the 1980s and 1990s.

More recent campaigning by anti-nuclear groups has related to several nuclear power plants including the Enrico Fermi Nuclear Power Plant, Indian Point Energy Center, Oyster Creek Nuclear Generating Station, Pilgrim Nuclear Generating Station, Salem Nuclear Power Plant, and Vermont Yankee Nuclear Power Plant. There have also been campaigns relating to the Y-12 Nuclear Weapons Plant, the Idaho National Laboratory, proposed Yucca Mountain nuclear waste repository, the Hanford Site, the Nevada Test Site, Lawrence Livermore National Laboratory, and transportation of nuclear waste from the Los Alamos National Laboratory.

Some scientists and engineers have expressed reservations about nuclear power, including: Barry Commoner, S. David Freeman, John Gofman, Arnold Gundersen, Mark Z. Jacobson, Amory Lovins, Arjun Makhijani, Gregory Minor, Joseph Romm and Benjamin K. Sovacool. Scientists who have opposed nuclear weapons include Linus Pauling and Eugene Rabinowitch.

Antitoxics groups
Antitoxics groups are a subgroup that is affiliated with the Environmental Movement in the United States, that is primarily concerned with the effects that cities and their by-products have on humans. This aspect of the movement is a self-proclaimed "movement of housewives". Concern around the issues of groundwater contamination and air pollution rose in the early 1980s and individuals involved in antitoxics groups claim that they are concerned for the health of their families. A prominent case can be seen in the Love Canal Homeowner's association (LCHA); in this case, a housing development was built on a site that had been used for toxic dumping by the Hooker Chemical Company. As a result of this dumping, the residents had symptoms of skin irritation, Lois Gibbs, a resident of the development, started a grassroots campaign for reparations. Eventual success led to the government having to purchase homes that were sold in the development.

Federal legislation in the 1970s
Prior to the 1970s the protection of basic air and water supplies was a matter mainly left to each state. During the 1970s, the primary responsibility for clean air and water shifted to the federal government. Growing concerns, both environmental and economic, from cities and towns as well as sportsman and other local groups, and senators such as Maine's Edmund S. Muskie, led to the passage of extensive legislation, notably the Clean Air Act of 1970 and the Water Pollution Control Act Amendments of 1972. Other legislation included the 1970 National Environmental Policy Act (NEPA), which established the Council on Environmental Quality; the Marine Protection, Research, and Sanctuaries Act of 1972; the Endangered Species Act of 1973, the Safe Drinking Water Act (1974), the Resource Conservation and Recovery Act (1976), the Water Pollution Control Act Amendments of 1977, which became known as the Clean Water Act, and the Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as the Superfund Act (1980). These laws regulated public drinking water systems, toxic substances, pesticides, and ocean dumping; and protected wildlife, wilderness, and wild and scenic rivers. Moreover, the new laws provide for pollution research, standard setting, contaminated site cleanup, monitoring, and enforcement.

The creation of these laws led to a major shift in the environmental movement. Groups such as the Sierra Club shifted focus from local issues to becoming a lobby in Washington and new groups, for example, the Natural Resources Defense Council and Environmental Defense, arose to influence politics as well. (Larson)

Renewed focus on local action
In the 1980s, President Ronald Reagan sought to curtail the scope of environmental protection taking steps such as appointing James G. Watt. The major environmental groups responded with mass mailings which led to increased membership and donations.

When industry groups lobbied to weaken regulation and a backlash against environmental regulations, the so-called wise use movement gained importance and influence.(Larson)

"Post-environmentalism"
In 2004, with the environmental movement seemingly stalled, some environmentalists started questioning whether "environmentalism" was even a useful political framework. According to a controversial essay titled "The Death of Environmentalism" (Michael Shellenberger and Ted Nordhaus, 2004) American environmentalism has been remarkably successful in protecting the air, water, and large stretches of wilderness in North America and Europe, but these environmentalists have stagnated as a vital force for cultural and political change.

Shellenberger and Nordhaus wrote, "Today environmentalism is just another special interest. Evidence for this can be found in its concepts, its proposals, and its reasoning. What stands out is how arbitrary environmental leaders are about what gets counted and what doesn't as 'environmental.' Most of the movement's leading thinkers, funders, and advocates do not question their most basic assumptions about who we are, what we stand for, and what it is that we should be doing." Their essay was followed by a speech in San Francisco called "Is Environmentalism Dead?" by former Sierra Club President, Adam Werbach, who argued for the evolution of environmentalism into a more expansive, relevant and powerful progressive politics. Werbach endorsed building an environmental movement that is more relevant to average Americans and controversially chose to lead Wal-Mart's effort to take sustainability mainstream.

These "post-environmental movement" thinkers argue that the ecological crises the human species faces in the 21st century are qualitatively different from the problems the environmental movement was created to address in the 1960s and 1970s. They argue that climate change and habitat destruction are global and more complex, therefore demanding far deeper transformations of the economy, the culture and political life. The consequence of environmentalism's outdated and arbitrary definition, they argue, is a political irrelevancy.

These "politically neutral" groups tend to avoid global conflicts and view the settlement of inter-human conflict as separate from regard for nature – in direct contradiction to the ecology movement and peace movement which have increasingly close links: while Green Parties, Greenpeace, and groups like the ACTivist Magazine regard ecology, biodiversity, and an end to non-human extinction as an absolute basis for peace, the local groups may not, and see a high degree of global competition and conflict as justifiable if it lets them preserve their own local uniqueness. However, such groups tend not to "burn out" and to sustain for long periods, even generations, protecting the same local treasures.

Local groups increasingly find that they benefit from collaboration, e.g. on consensus decision-making methods, or making simultaneous policy, or relying on common legal resources, or even sometimes a common glossary. However, the differences between the various groups that make up the modern environmental movement tend to outweigh such similarities, and they rarely co-operate directly except on a few major global questions. In a notable exception, over 1,000 local groups from around the country united for a single day of action as part of the Step It Up 2007 campaign for real solutions to global warming.

Groups such as The Bioregional Revolution are calling on the need to bridge these differences, as the converging problems of the 21st century they claim compel the people to unite and to take decisive action. They promote bioregionalism, permaculture, and local economies as solutions to these problems, overpopulation, global warming, global epidemics, and water scarcity, but most notably to "peak oil" – the prediction that the country is likely to reach a maximum in global oil production which could spell drastic changes in many aspects of the residents' everyday lives.

Criticisms
Some people are skeptical of the environmental movement and feel that it is more deeply rooted in politics than science. Although there have been serious debates about climate change and effects of some pesticides and herbicides that mimic animal sex steroids, science has shown that some of the claims of environmentalists have credence.

Novelist Michael Crichton appeared before the U.S. Senate Committee on Environment and Public Works on September 28, 2005, to address concerns and recommended the employment of double-blind experimentation in environmental research. Crichton suggested that because environmental issues are so political in nature, policymakers need neutral, conclusive data to base their decisions on, rather than conjecture and rhetoric, and double-blind experiments are the most efficient way to achieve that aim.

A consistent theme acknowledged by both supporters and critics (though more commonly vocalized by critics) of the environmental movement is that we know very little about the Earth we live in. Most fields of environmental studies are relatively new, and therefore what research we have is limited and does not date far enough back for us to completely understand long-term environmental trends. This has led a number of environmentalists to support the use of the precautionary principle in policy-making, which ultimately asserts that we don't know how certain actions may affect the environment and because there is reason to believe they may cause more harm than good we should refrain from such actions.

Elitist
In the December 1994 Wild Forest Review, Alexander Cockburn and Jeffrey St. Clair wrote "The mainstream environmental movement was elitist, highly paid, detached from the people, indifferent to the working class, and a firm ally of big government.…The environmental movement is now accurately perceived as just another well-financed and cynical special interest group, its rancid infrastructure supported by Democratic Party operatives and millions in grants from corporate foundations."

Many environmental organizations lack diversity, including often white women as the main demographic. However, environmental problems are experienced differently by different social groups, including black versus white groups. For the middle class white population in the US, environmental issues have often included pollution, barriers to recreational activities, etc.. On the other hand, for people of color, environmental issues were often life or death including issues of "smoke, soot, dust, . . . fumes gases, stench, and carbon monoxide." In the past environmental organizations have focused "on preserving natural resources and endangered species instead of protecting people of color from hazardous waste sites being built in their communities". When environmental organizations appoint people of color to positions of leadership, the focus will often shift more towards focus on these major, life-threatening issues. However, a significant 2014 State of Diversity in Environmental Organizations study found that the percentage of minorities working for environmental organizations has never exceeded 16% and less than 12% have achieved positions of leadership.

Wilderness myth
Historians have criticized the modern environmental movement for having romantic idealizations of wilderness. William Cronon writes "wilderness serves as the unexamined foundation on which so many of the quasi-religious values of modern environmentalism rest." Cronon claims that "to the extent that we live in an urban-industrial civilization but at the same time pretend to ourselves that our real home is in the wilderness, to just that extent we give ourselves permission to evade responsibility for the lives we actually lead."

Similarly Michael Pollan has argued that the wilderness ethic leads people to dismiss areas whose wildness is less than absolute. In his book Second Nature, Pollan writes that "once a landscape is no longer 'virgin' it is typically written off as fallen, lost to nature, irredeemable."

Debates within the movement
Within the environmental movement, an ideological debate has taken place between those with an ecocentric viewpoint and an anthropocentric viewpoint. The anthropocentric view has been seen as the conservationist approach to the environment with nature viewed, at least in part, as a resource to be used by man. In contrast to the conservationist approach the ecocentric view, associated with John Muir, Henry David Thoreau and William Wordsworth referred to as the preservationist movement. This approach sees nature in a more spiritual way. Many environmental historians consider the split between John Muir and Gifford Pinchot. During the preservation/conservation debate, the term preservationist becomes to be seen as a pejorative term.

While the ecocentric view focused on biodiversity and wilderness protection the anthropocentric view focuses on urban pollution and social justice. Some environmental writers, for example, William Cronon have criticized the ecocentric view as have a dualist view as a man being separate from nature. Critics of the anthropocentric viewpoint contend that the environmental movement has been taken over by so-called leftist with an agenda beyond environmental protection.

Environmentalism and politics

Environmentalists gained popularity in American politics after the creation or strengthening of numerous US environmental laws, including the Clean Air Act, Clean Water Act, and the formation of the United States Environmental Protection Agency (EPA) in 1970. These successes were followed by the enactment of a series of laws regulating waste including the Resource Conservation and Recovery Act; Toxic substances, (Toxic Substances Control Act); Pesticides (FIFRA: Federal Insecticide, Fungicide, and Rodenticide Act); clean-up of polluted sites (Superfund); protection of endangered species (Endangered Species Act).

Fewer environmental laws have been passed in the last decade as corporations and other conservative interests have increased their influence over American politics. Corporate cooperation against environmental lobbyists has been organized by the Wise Use group. At the same time, many environmentalists have been turning toward other means of persuasion, such as working with business, community, and other partners to promote sustainable development. Since the 1970s, coalitions and interests groups have directed themselves along the democrat and republican party lines.

Much environmental activism is directed towards conservation as well as the prevention or elimination of pollution. However, conservation movements; ecology movements; peace movements; green parties; green- and eco-anarchists often subscribe to very different ideologies, while supporting the same goals as those who call themselves "environmentalists". To outsiders, these groups or factions can appear to be indistinguishable.

As human population and industrial activity continue to increase, environmentalists often find themselves in serious conflict with those who believe that human and industrial activities should not be overly regulated or restricted, such as some libertarians.

Environmentalists often clash with others, particularly corporate interests, over issues of the management of natural resources, like in the case of the atmosphere as a "carbon dump", the focus of climate change, and global warming controversy. They usually seek to protect commonly owned or unowned resources for future generations.

Environmental justice in the United States
Environmental justice is a movement that began in the U.S. in the 1980s and seeks an end to environmental racism. Environmental justice (EJ) did not come into regular use until 1982 when Warren County, a predominantly African American community, became a site for toxic waste dumping. This sparked protests which eventually led to the arrest of 414 peaceful African American protestors. In 1987, the publication of the United Church of Christ (UCC) Commission for Racial Justice’s report “Toxic Wastes and Race in the United States" offered the first clear description of environmental racism (ER). ER looks different in different communities, and each context requires distinct policies and actions. Closely related to ER, the environmental justice movement is also grassroots in practice and “importantly, a movement, which means that it starts and lives with the people”.

Often, low-income and minority communities are located close to highways, garbage dumps, and factories, where they are exposed to greater pollution and environmental health risk than the rest of the population. The Environmental Justice movement seeks to link "social" and "ecological" environmental concerns, while at the same time keeping environmentalists conscious of the dynamics in their own movement, i.e. racism, sexism, homophobia, classicism, and other malaises of the dominant culture.

In 1991, the First National People of Color Environmental Leadership Summit drafted the 17 principles of environmental justice calling for an “appreciation of our diverse cultural perspectives” along with the “ecological unity and the interdependence of all species, and the right to be free from ecological destruction”. Throughout the EJ movement there has been a focus on everyone being safe from environmental harms including pollution, hazardous wastes, land access, and also the ability of all to participate in decision-making. Over time, the main principle that has developed within the movement is “We speak for ourselves” meaning those within the community experiencing the environmental injustice should be the leaders of change.

Major US environmental justice organizations

 * Communities for a Better Environment: An organization founded in 1978 in San Francisco, California with the main mission of building power for low-income and communities of color to ultimately achieve environmental justice. They focus on reducing pollution and helping to create healthy, environmentally-friendly communities. In order to create action to tackle such an encompassing mission, CBE follows a threefold approach including community organizing, legal advocacy, and science. CBE, focuses on bringing marginalized communities together to create power and hence change in environmental decisions in their local areas. Volunteers from throughout the community come together to participate in door-knocking, community meetings, school groups, and various other educational opportunities. Today Communities for a Better Environment has expanded into Wisconsin and Minnesota.

 * West Harlem Environmental Action: An organization founded in 1988 in New York city by community members foregrounding environmental racism within their community. West Harlem Environmental Action, now known as We Act, works on issues of climate justice, ensuring community-based participatory research, and participatory democracy are upheld within their organization and throughout the Harlem community. They mainly tackle issues of air regulation, pollution, and fair land use. Today, We Act has expanded to Washington, D.C.
 * Indigenous Environmental Network: An organization founded in 1990 in North America with the main mission of uniting indigenous communities to protect "sacred sites, land, water, air, natural resources, health of both our people and all living things, and to build economically sustainable communities". IEN works with tribes to increase environmental education, organization, and in turn inspire action. IEN has expanded its reach globally, in recent years, providing global meetings to Indigenous communities on indigenous environmental issues.
 * Climate Justice Alliance: An organization founded in 2013 in Detroit, Michigan with the main mission of uniting communities and organizations to following the just transition theory, versus the exploitative economic system in place. They place a strong emphasis on race, gender, and class in creating this transition. With creating this link between organizations and communities they hope to inspire action towards confronting climate change and the economy that creates it. Climate Justice Alliance focuses on making the transition within local communities to "clean community energy, regional food systems, zero waste, efficient, affordable, and durable housing, public transportation, ecosystem restoration and stewardship within scientific planetary boundaries". Climate Justice Alliance has currently expanded in Texas, Florida, Puerto Rico, and North Carolina.

Environmental rights
Many environmental lawsuits turn on the question of who has standing; are the legal issues limited to property owners, or does the general public have a right to intervene? Christopher D. Stone's 1972 essay, "Should trees have standing?" seriously addressed the question of whether natural objects themselves should have legal rights, including the right to participate in lawsuits. Stone suggested that there was nothing absurd in this view, and noted that many entities now regarded as having legal rights were, in the past, regarded as "things" that were regarded as legally rightless; for example, aliens, children and women. His essay is sometimes regarded as an example of the fallacy of hypostatization.

One of the earliest lawsuits to establish that citizens may sue for environmental and aesthetic harms was Scenic Hudson Preservation Conference v. Federal Power Commission, decided in 1965 by the Second Circuit Court of Appeals. The case helped halt the construction of a power plant on Storm King Mountain in New York State. See also United States environmental law and David Sive, an attorney who was involved in the case.

Conservation biology is an important and rapidly developing field. One way to avoid the stigma of an "ism" was to evolve early anti-nuclear groups into the more scientific Green Parties, sprout new NGOs such as Greenpeace and Earth Action, and devoted groups to protecting global biodiversity and preventing global warming and climate change. But in the process, much of the emotional appeal, and many of the original aesthetic goals were lost. Nonetheless, these groups have well-defined ethical and political views, backed by science.

Radical environmentalism
Main article: Radical environmentalism

While most environmentalists are often mainstream and peaceful, other groups are more radical in their approach. Adherents of radical environmentalism and ecological anarchism are involved in direct action campaigns to protect the environment. Some campaigns have employed controversial tactics including sabotage, blockades, and arson, while most use peaceful protests such as marches, tree sitting, and the like. There is substantial debate within the environmental movement as to the acceptability of these tactics, but almost all environmentalists condemn violent actions that can harm humans.

Clashes by police
In 2023, for the first time in the history of the United States, the police killed an environmental activist during a protest. The protesters were camping in Atlanta's South River Forest, a natural area that the City of Atlanta and Police planned to raze in order to erect a police training facility to be called "Cop City." Police attacked protesters on 18 January 2023. One protester, Tortuguita or, Manuel Esteban Páez Terán was killed and seven more were arrested.