evgeny yauhenio's List: TTC_philosophy_of_science

a philosophical doctrine formulated in Vienna in the 1920s, according to which scientific knowledge is the only kind of factual knowledge and all traditional metaphysical doctrines are to be rejected as meaningless.

The Logical Positivist school differs from earlier empiricists and positivists (David Hume, Ernst Mach) in holding that the ultimate basis of knowledge rests upon public experimental verification rather than upon personal experience. It differs from Auguste Comte and J.S. Mill in holding that metaphysical doctrines are not false but meaningless—that the “great unanswerable questions” about substance, causality, freedom, and God are unanswerable just because they are not genuine questions at all. This last is a thesis about language, not about nature, and is based upon a general account of meaning and of meaninglessness. All genuine philosophy (according to the group that came to be called the Vienna Circle) is a critique of language; and (according to some of its leading members) its result is to show the unity of science—that all genuine knowledge about nature can be expressed in a single language common to all the sciences.

a group of philosophers, scientists, and mathematicians formed in the 1920s that met regularly in Vienna to investigate scientific language and scientific methodology. The philosophical movement associated with the Circle has been called variously logical positivism, logical empiricism, scientific empiricism, neopositivism, and the unity of science movement. The work of its members, although not unanimous in the treatment of many issues, was distinguished, first, by its attention to the form of scientific theories, in the belief that the logical structure of any particular scientific theory could be specified quite apart from its content. Second, they formulated a verifiability principle or criterion of meaning, a claim that the meaningfulness of a proposition is grounded in experience and observation. For this reason, the statements of ethics, metaphysics, religion, and aesthetics were held to be assertorically meaningless. Third, and as a result of the two other points, a doctrine of unified science was espoused. Thus, no fundamental differences were seen to exist between the physical and the biological sciences or between the natural and the social sciences.

The demarcation problem in the philosophy of science is about how and where to draw the lines around science. The boundaries are commonly drawn between science and non-science, between science and pseudoscience, and between science and religion. A form of this problem, known as the generalized problem of demarcation subsumes all three cases. The generalized problem looks for criteria for deciding which of two theories is the more scientific.
The philosopher Karl Popper noticed that the philosophers of the Vienna Circle had mixed two different problems and had accordingly given them a single solution: verificationism. In opposition to this view, Popper emphasized that a theory might well be meaningful without being scientific, and that, accordingly, a criterion of meaningfulness may not necessarily coincide with a criterion of demarcation. His own falsificationism, thus, is not only an alternative to verificationism; it is also an acknowledgment of the conceptual distinction that previous theories had ignored.

Popper saw demarcation as a central problem in the philosophy of science. In place of verificationism he proposed falsification as a way of determining if a theory is scientific or not. If a theory is falsifiable, then it is scientific; if it is not falsifiable, then it is not science. Some have used this principle to cast doubt on the scientific validity of many disciplines (such as macroevolution and physical cosmology).

Falsifiability (or refutability) is the logical possibility that an assertion can be shown false by an observation or a physical experiment. That something is "falsifiable" does not mean it is false; rather, that if it is false, then this can be shown by observation or experiment. Falsifiability is an important concept in science and the philosophy of science. The term "Testability" is related but more specific; it means that an assertion can be falsified through experimentation alone.

Popper stressed that unfalsifiable statements are still very important for science and are often contained in scientific theories as unfalsifiable consequences. For example, while "all men are mortal" is unfalsifiable, it is still contained as a consequence of the falsifiable theory that "every man dies before he reaches the age of 150 years". Similarly, the ancient metaphysical idea of the existence of atoms has led to corresponding falsifiable modern theories. Popper invented the notion of metaphysical research programs to name such ideas.

In contrast to Positivism, which held that statements are senseless if they cannot be verified or falsified, Popper denied that falsifiability somehow makes scientific theories special. According to Popper, falsifiability is merely a special case of the much more general notion of criticizability, even though he admitted that falsification is one of the most effective methods by which theories can be criticized.

A verificationist is someone who adheres to the verification principle proposed by A.J. Ayer in Language, Truth and Logic (1936), a principle and criterion for meaningfulness that requires a non-analytic, meaningful sentence to be empirically verifiable. The term can also, more rarely, refer to a person believing in an altered form, such as the falsification principle. It was hotly disputed amongst verificationists whether the empirical verification itself must be possible in practice or merely in principle, for example, a claim that the world came into existence a short time ago exactly as it is today (with misleading apparent traces of a longer past), would be judged meaningless by a verificationist because it is neither an analytic claim nor a verifiable claim. Ayer distinguished between strong and weak verification.

Strong verification refers to statements which are directly verifiable, that is, a statement can be shown to be correct by way of empirical observation. For example, 'There are human beings on Earth.'

Weak verification refers to statements which are not directly verifiable, for example 'Yesterday was a Monday'. The statement could be said to be weakly verified if empirical observation can render it highly probable.

Popper’s emphasis on criticism stems from his rejection of the most straightforward criterion of demarcation, according to which scientific claims are special because they are confirmed by observational evidence and because they explain observations.
1. Pseudosciences, such as astrology, are chock full of appeals to observational evidence. Observation, for Popper, is cheap. It is essentially interpretation of experience in terms of one’s theory. The
pseudoscientist finds confirming evidence everywhere (for example, in the many case studies of Freud and Adler).
2. Furthermore, apparent counterevidence can be turned aside or even turned into confirming evidence by a clever pseudoscientist. Freud and Adler had ready explanations for any observational result.
3. For Popper, no evidence falsifies a pseudoscientific claim and almost everything confirms it. As a result, Popper came to see the two standard virtues of scientific theories -- explanatory power and
confirmation by a large number of instances -- has closer to being vices than virtues.
4. Fitting the data well is, thus, not the mark of a scientific theory; a good scientific theory should be informative, surprising, and in a certain sense, improbable.

Arthur Stanley Eddington, OM, FRS (28 December 1882 – 22 November 1944) was a British astrophysicist of the early 20th century. The Eddington limit, the natural limit to the luminosity of stars, or the radiation generated by accretion onto a compact object, is named in his honour.

He is famous for his work regarding the Theory of Relativity. Eddington wrote a number of articles which announced and explained Einstein's theory of general relativity to the English-speaking world. World War I severed many lines of scientific communication and new developments in German science were not well known in England. He also conducted an eclipse expedition in 1919 that provided one of the earliest confirmations of relativity, and he became known for his popular expositions and interpretations of the theory.

"The Mendelian underpinning of modern Darwinism has been well tested, and so has the theory of evolution which says that all terrestrial life has evolved from a few primitive unicellular organisms, possibly even from one single organism.

However, Darwin's own most important contribution to the theory of evolution, his theory of natural selection, is difficult to test. There are some tests, even some experimental tests; and in some cases, such as the famous phenomenom known as "industrial melanism", we can observe natural selection happening under our very eyes, as it were. Nevertheless, really severe tests of the theory of natural selection are hard to come by, much more so than tests of otherwise comparable theories in physics or chemistry"

To call something unscientific is not to call it scientifically worthless.
1. Popper thought that Freud, Marx, and Adler said some true and important things.
2. Furthermore, metaphysical frameworks, such as atomism (which was not testable for centuries after it was proposed), can help scientists formulate testable hypotheses.
3. Popper even thought for awhile that Darwin’s principle of natural selection was an ultimately unscientific doctrine. He later changed his mind about this, arguing that the Darwinian claim about survival of the fittest is not a mere definition of fitness (and, hence, unfalsifiable) but instead implies historical hypotheses about the causes of traits in current populations.

American experimental physicist noted for his studies
of materials at high temperatures and pressures. For his work he was awarded the Nobel Prize for Physics in 1946.

During a course of lectures that Bridgman gave in 1914 on advanced electrodynamics, he was struck by the obscurities and ambiguities inherent in defining scientific ideas. This led him to the “operational” approach to scientific meaning, discussed in his first philosophical book, The Logic of Modern Physics (1927, reprinted 1960). He defined physical concepts (e.g., length) in terms of the operations, both physical and mental, involved in their measurement. Since all measurements are relative to the frame of reference of the observer, concepts are also relative; length, for example, is a different concept when measured terrestrially than when measured astronomically. Bridgman asserted that it is meaningless to interpret physical concepts except insofar as they are capable of observation.

Operationalization is the process of defining a fuzzy concept so as to make the concept measurable in form of variables consisting of specific observations. In a wider sense it refers to the process of specifying the extension of a concept.

Even the most basic concepts in science, such as "length," are defined through the operations by which we measure them. This derives from the discovery of Percy Williams Bridgman, whose methodological position is called operationalism. The fact that we in practice measure "length" in different ways (it's impossible to use a measuring rod if we want to measure the distance to the Moon, for example) must mean that "length" logically isn't one concept but many. Each concept is defined by the measuring operations used.

Bridgman notes that in the theory of relativity we see how concepts like "length" and "duration" split into actually different concepts. As part of the process of refining a physical theory, it may be found that what was one concept is, in fact, two or more distinct concepts. However, Bridgman proposes that if we only stick to operationally defined concepts, this will never happen

Theory due to American physicist Percy Williams Bridgman (1882-1961) and saying that scientific concepts must be defined in terms of the operations by which they are measured or applied.

The theory is akin to the verifiability principle in its strongest form, identifying meaning with method of verification; but applies to concepts rather than sentences or propositions, and is in the spirit of logical positivism.

It has untoward results, such as that length as measured by astronomers is a different concept from length as measured by ordinary people using a tape-measure.

. Operationalism has been enormously influential in many scientific disciplines, but many philosophers think operationalism represents a too-stringent way of tying down our concepts in experiential terms.
A. Operationalizing weight in terms of a pan balance assumes that no “additional” forces are affecting the pans differently. But how are we to specify “no additional forces” in observational and/or operational terms?
B. Our confidence that two different kinds of thermometers measure the same “stuff” relies on an idea of the thing being measured that far outruns the measurings. If we were trying to build a device that would measure the temperature of the Sun, we’d be relying on the notion of a good temperature-measuring device. But at that point, we have given up reducing the notion of temperature to what we can actually measure, and that was supposed to be the point of Einstein’s story.

Distinction first formulated by the German philosopher Immanuel Kant (1724-1804), adopted as a fundamental principle in linguistic semantics.

An analytic or necessary truth ('sentence' in linguistics) is true by virtue of its meaning: 'All bachelors are unmarried men'.

A synthetic or contingent truth is true by virtue of empirical fact: 'Grass is green' is not necessarily true, but only if grass is green.

Locke investigated the scope of our knowledge by investigating its sources. He claimed that experience is the source of all the material of thought: “Nothing is in the mind that was not first in the senses.”
1. An idea, for Locke, is what is in the mind when the mind thinks. Ideas are mind-dependent; they are (more or less) literally in minds. The things I directly perceive are sights and sounds, not physical objects.
2. Simple ideas are given in experience. Innate mental powers (notably combination and abstraction) allow us to refine and extend our simple ideas. Abstraction lets us focus on a part of a presented idea (for example, the blueness of the sky), and these parts can be recombined to form ideas of things never presented in experience, such as unicorns.
D. Locke recognized the limitations of what experience puts us in a position to know. We have very little understanding of the inner nature of material substances, and we are unable to form any useful idea of how such substances produce in us many of the ideas they generate.
E. Locke’s highly influential view represents something of a standard empiricist bargain. We gain systematic resources for clarifying our ideas, and we pay for this clarification by realizing that we don’t get to know as much or even say as much as we might have thought we could.

Berkeley saw himself as purging philosophy of its tendencies toward skepticism and atheism, but he was much misunderstood by his contemporaries.
B. It is perhaps understandable that his contemporaries thought him a skeptic, because Berkeley denied the existence of matter. A material object is supposed to be something that “holds” or “supports” its properties,
and Berkeley goes so far as to deny that we have an idea of material substance.
1. We have no direct experience of matter. What does it look or feel like?
2. Berkeley denied that we can obtain a legitimate idea of matter through abstraction. We cannot imagine a thing without its properties.
3. Locke had already admitted that it was mysterious how material objects produced ideas in us.
C. For Berkeley, God simply produces ideas in us directly. God does not use matter as an intermediary way to cause our experiences.

. As a result, Berkeley was the first empiricist to get over the idea that we need to get behind or beyond
experience.
1. For Berkeley, the patterns in our experience are the world itself. God has set things up so that if we formulate and apply, say, Newton’s laws of motion, we can predict what experiences we will have.
2. All science can or should be is the development of rules for predicting what experiences we will have.

Irish clergyman George Berkeley completed his most significant philosophical work before turning thirty, during his years as a student, fellow, and teacher at Trinity College, Dublin. Using material from his collegiate notebooks on philosophy, he developed a series of texts devoted to various aspects of a single central thesis: that matter does not exist. In An Essay Towards a New Theory of Vision (1709), for example, he argued that the phenomena of visual sensation can all be explained without presupposing the reality of external material substances; the objects we see are merely ideas in our minds and that of god. Berkeley spent most of his mature years in London, travelling briefly to Rhode Island in the vain hope of securing financial support for a college to be established in Bermuda.

It is the earlier immaterialist philosophy, in which he employed strictly empiricist principles in defence of the view that only minds or spirits exist, for which Berkeley is now remembered. He opened A Treatise concerning the Principles of Knowledge (1710) rather technically, with an extended attack on Locke's theory of abstract ideas. The book continues with arguments designed to show that sensible qualities—both secondary and primary—can exist only when perceived, as ideas in our minds. Since physical objects are, on Berkeley's view, nothing more than collections of such qualities, these sensible objects, too, are merely ideas. In what he believed to be his most devastating point, Berkeley argued that it is literally inconceivable that anything like a material substance could exist independently of the spirits or active thinking substances that perceive it. Berkeley Through the remainder of the Principles, Berkeley tried to distinguish his position from that of Malebranche, defended its application to the achievements of modern science, and extolled its beneficial consequences for traditional religion.

Hume's fork is often stated in such a way that statements are divided up into two types:

* Statements about ideas - these are analytic, necessary statements that are knowable a priori.
* Statements about the world - these are synthetic, contingent, and knowable a posteriori.

In modern terminology, members of the first group are known as analytic propositions and members of the latter as synthetic propositions. This terminology comes from Kant (Introduction to Critique of Pure Reason, Section IV).

Into the first class fall statements such as "2 + 2 = 4", "all bachelors are unmarried", and truths of mathematics and logic. Into the second class fall statements like "the sun rises in the morning", "the Earth has precisely one moon", and "water freezes at 32 degrees Fahrenheit".

Hume wants to prove that certainty does not exist in science.

First, Hume notes that statements of the second type can never be entirely certain, due to the fallibility of our senses, the possibility of deception (see e.g. the modern brain in a vat theory) and other arguments made by philosophical skeptics. It is always logically possible that any given statement about the world is false. (Note that statements like "either the Earth has precisely one moon, or not" are really truths of logic, and say nothing about the world).

Second, Hume claims that our belief in cause-and-effect relationships between events is not grounded on reason, but rather arises merely by habit or custom. Suppose one states: "Whenever someone on earth lets go of a rock, it falls." While we can grant that in every instance thus far when a rock was dropped on Earth it went down, this does not give us any reason to think that in the future, rocks will fall when in the same circumstances. It would give us reason only if we add as a premise that the future will resemble the past. But that isn't something that we can know based on past experience -- all past experience could tell us is that in the past, the future has resembled the past.

Third, Hume notes that relations of ideas can be used only to prove other relations of ideas, and mean nothing outside of the context of how they relate to each other, and therefore tell us nothing about the world. Take the statement "An equilateral triangle has three sides of equal length." While some earlier philosophers (most notably Plato and Descartes) held that logical statements such as these contained the most formal reality, since they are always true and unchanging, Hume held that, while true, they contain no formal reality, because the truth of the statements rests on the definitions of the words involved, and not on actual things in the world, since there is no such thing as a true triangle or exact equality of length in the world. So for this reason, relations of ideas cannot be used to prove mat

W. V. O. Quine's paper "Two Dogmas of Empiricism", published in 1951, is one of the most celebrated papers of twentieth century philosophy in the analytic tradition. According to Harvard professor of philosophy Peter Godfrey-Smith, this "paper [is] sometimes regarded as the most important in all of twentieth-century philosophy". [1] The paper is an attack on two central parts of the logical positivists' philosophy. One is the distinction between analytic truths and synthetic truths, explained by Quine as truths grounded only in meanings and independent of facts, and truths grounded in facts. The other is reductionism, the theory that each meaningful statement gets its meaning from some logical construction of terms that refers exclusively to immediate experience.

Ideas

- All human thinking, both for individual persons and for historical cultures, follows the law of the three stages: first seeking explanation in animistic purposes (the theological stage), then in abstract entities (the metaphysical stage), and finally in lawful observable correlations among variables (the positive stage).

- There is a definite prder among the positive sciences, in which the lower, simpler, and more general are presupposed by the higher, more complex, and more particular; this ordering provides both for the unity of the sciences, as successive branches from a common stem, and also for the recognition of historically emergent distinctive mehods within different empirical subject matters.

- The crowning science, the most complex and consequently the last to emerge as an empirical domain of invariant lawfulness, is sociology.

- Sociology and positive philosophy finally will ground an urgently needed reorganization of politics, ethics, and religion.

- Religious ritual, when brought into harmony with scientific intellect, is vital for the cultivation of feeling, thus providing motivation for the transformation and nurture of healthy society.

The logical positivists made philosophy of science a major subfield for the first time. Their approach to the field dominated for decades.
A. They were highly impressed by Einstein’s work and other developments in physics and highly unimpressed by much of 19th- and early-20th-century German philosophy. To them, the philosophy of the day seemed
like armchair speculation, much of which stood in the way of scientific progress.
B. They were less worried than Popper was about pseudosciences and more worried than he was about metaphysics and about philosophy getting in the way of physics. This leads, as we will see, to a different approach to the demarcation problem.
C. The positivism part of logical positivism derived from the 19th
-century French thinker Auguste Comte and reflects his animus against traditional metaphysics.
D. The logical part of logical positivism reflects the positivists’ belief that mathematical logic provided tools
with which a new and improved version of empiricism could be built, one that would be favorable to science and unfavorable to metaphysics.
E. This new version of empiricism grasped the other option presented by Hume’s fork. For the positivists, the philosopher deals in relations of ideas, not matters of fact. Philosophy clarifies linguistic problems and exhibits the relationships between scientific statements and experience.