PHI 306 Philosophy of ScienceFall 2014 - Garns Philosophy of science PHI 306 - Fall 2014

PHI 306 Philosophy of Science Fall 2014 - Garns

Philosophy of sciencePHI 306 - Fall 2014


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

Questions we’ll explore


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

What is science?

What is its aim and what are its methods?

How does science differ from philosophy?

What would a philosophy of science contribute to our understanding of science?

How does science differ from pseudoscience?

How do sciences differ from each other? Is there something common to all science?


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

What is it for an observation to confirm or support a theory?

How is confirmation related to deductive logic and inductive logic?

Is the relation between theory and evidence formal or informal?

What does it mean to increase the probability that a theory is true?

Does our evidence underdetermine our theories?

How (and when) does new evidence warrant a change in our beliefs?


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

What is a (good) scientific explanation?

How are explanations related to predictions?

What is a law of nature and why are they important to science?

Can the terms (and explanations) of one theory be reduced to the terms (and explanations) of another theory?


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

Can science make progress?

How do we decide when to reject an old theory and accept a new one? Is change in science always (ever) rational?

What is a scientific framework?

Are all observations (and the terms used to refer to them) theory-laden?

Does science describe reality as it is?

Should we believe that unobservable entities really exist?


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

What are the values of science and of scientists?

Should values influence science?

Can science be objective?

Are there social, gender, political biases in science?

Are our choices in science (always, ever) rational?


Course Outline

• Demarcation

• Confirmation

• Explanation

• Progress

• Values

• Social Science

How are social sciences different from and similar to natural sciences?

Do social science facts reduce to natural science facts?

Do the social sciences interpret or discover?

How reliable are functional explanations?

Are (folk) psychological explanations reliable?


The Philosophy of Science

• Understanding science (practice, aims, purpose)

• Normative and descriptive projects

• Critiquing

• Being a scientist and being a philosopher of science


What is science?

• Try to define science

• How is science (scientific) similar or dissimilar to

• Art (artistic)

• History (historical)

• Astrology

• Rocking Horse Winner


Demarcation

• What is science? How do we decide?

• Conceptual analysis (necessary and sufficient conditions)

• Association and affiliation (credentials)

• Paradigm cases

• The aims of science

• The scientific method


Method and Logic

• Deduction v. Induction

• NOT: deduction argues from general to specific and induction argues from specific to general.

• BETTER:

• deductive arguments are intended to be valid, the conclusion follows necessarily from the premises.

• inductive arguments are intended to be strong, the conclusion is likely to be true given the premises.


Inductivism

• Science is distinguished by its use of inductive logic to gain knowledge about the world.

• Enumerative induction; generalization

• Gather facts (neutral observations); generalize over those facts (patterns, laws, theories); use generalizations (with initial conditions) to explain and predict

• Induction lets us generalize; deduction reveals predictions and explanations1. Laws and theories

2. Initial conditions3. Predictions and Explanations


Problems for inductivism

• What counts as a good inductive argument?

• Can laws be derived from observations?

• Can we learn about unobservables?

• Can induction be justified?


Inference to the best explanation

“The inference to the best explanation” corresponds approximately to what others have called “abduction,” the method of hypothesis,“ “hypothetic inference,” “the method of elimination,” “eliminative induction,” and “theoretical inference.”I prefer my own terminology because I believe that it avoids most of the misleading suggestions of the alternative terminologies.

In making this inference one infers, from the fact that a certain hypothesis would explain the evidence, to the truth of that hypothesis. In general, there will be several hypotheses which might explain the evidence, so one must be able to reject all such alternative hypotheses before one is warranted in making the inference. Thus one infers, from the premise that a given hypothesis would provide a “better” explanation for the evidence than would any other hypothesis, to the conclusion that the given hypothesis is true.

- Gilbert Harman


Logical Positivism

• The Vienna Circle

• Empiricist Background

• Rejection of Synthetic A Priori Knowledge: Anti-metaphysics

• Observation and Theoretical Statements + Logic

• Context of Discovery and Context of Justification


Verificationism

We say that a sentence is factually significant [meaningful] to any given person, if and only if, [she or] he knows how to verify the proposition which it purports to express—that is, if [she or] he knows what observations would lead [her or] him, under certain conditions, to accept the proposition as being true, or reject it as being false. (A.J. Ayer)

When are we sure that the meaning of a question is clear? Obviously if and only if we are able to exactly describe the conditions in which it is possible to answer yes, or, respectively, the conditions in which it is necessary to answer with a no. The meaning of a question is thus defined only through the specification of those conditions…. The definition of the circumstances under which a statement is true is perfectly equivalent to the definition of its meaning. … a statement has a meaning if and only if the fact that it is true makes a verifiable difference. (M. Schlick, 'Positivismus und Realismus' in Erkenntnis, 3, 1932).


Problems

• Meaningful statements are called meaningless

• positive universals• negative existentials• past and future statements

• Is the principle meaningful?

• Quine-Duhem thesis; meaning holism


POpper

• Science differs from

• Marx’s theory of history

• Freud’s theory of psychoanalysis

• Adler’s theory of individual psychology


Confirmation

I found that those of my friends who were admirers of Marx, Freud, and Adler, were impressed by a number of points common to these theories, and especially by their apparent explanatory power. These theories appear to be able to explain practically everything that happened within the fields to which they referred. The study of any of them seemed to have the effect of an intellectual conversion or revelation, open your eyes to a new truth hidden from those not yet initiated. Once your eyes were thus opened you saw confirmed instances everywhere: the world was full of verifications of the theory. Whatever happened always confirmed it. Thus its truth appeared manifest; and unbelievers were clearly people who did not want to see the manifest truth; who refuse to see it, either because it was against their class interest, or because of their repressions which were still “un-analyzed” and crying aloud for treatment.

The most characteristic element in this situation seemed to me the incessant stream of confirmations, of observations which “verified” the theories in question….

- Karl Popper


Falsifiability

• Confirmation is too lenient.


Falsifiability


• Falsifiability is a defining feature of science


Falsifiability



• We should seek bold hypotheses


Falsifiability



• We should seek bold hypotheses

• Successful predictions can corroborate but not confirm


Crucial Tests

With Einstein's theory the situation was strikingly different. Take one typical instance — Einstein's prediction, just then confirmed by the finding of Eddington's expedition. Einstein's gravitational theory had led to the result that light must be attracted by heavy bodies (such as the sun), precisely as material bodies were attracted. As a consequence it could be calculated that light from a distant fixed star whose apparent position was close to the sun would reach the earth from such a direction that the star would seem to be slightly shifted away from the sun; or, in other words, that stars close to the sun would look as if they had moved a little away from the sun, and from one another. This is a thing which cannot normally be observed since such stars are rendered invisible in daytime by the sun's overwhelming brightness; but during an eclipse it is possible to take photographs of them. If the same constellation is photographed at night one can measure the distance on the two photographs, and check the predicted effect.

- Popper


Questions

• Are pseudosciences not science or bad science?


Lakatos

Popper's criterion ignores the remarkable tenacity of scientific theories. Scientists have thick skins. They do not abandon a theory merely because facts contradict it. They normally either invent some rescue hypothesis to explain what they then call a mere anomaly or, if they cannot explain the anomaly, they ignore it, and direct their attention to other problems. - Lakatos


Questions


• Should we sometimes question the falsifying observation?

• Underdetermination: confronted with potential refutation, might we question the auxiliary hypotheses?


Questions


• Should we sometimes question the falsifying observation?

• Underdetermination: confronted with potential refutation, might we question the auxiliary hypotheses?

• Observations themselves involves theory


Questions

• How does theory change?


Questions


• Compare Popper’s theory with Darwinian evolution (variation and natural selection)


Questions


• Compare Popper’s theory with Darwinian evolution (variation and natural selection)

• Statistical hypotheses: What about a statement that claims that a particular observation is unlikely (not forbidden)?


Practical Problem

Suppose we are building a bridge, and we need to use physical theories to tell us which designs are stable and will support the weight that the bridge must carry....

Suppose we have to choose between (1) a theory that has been tested many times and has passed every test, and (2) a brand new theory that has just been conjectured and has never been tested. Neither theory has been falsified.

...what can Popper say about this choice?

- Godfrey-Smith


Demarcation

• Is there a recipe for distinguishing science from pseudoscience?

• Logic

• Psychology

• Practice

• Society

• Science or Scientific


Creation-science

"Creation-science" means the scientific evidences for creation and inferences from those scientific evidences. Creation-science includes the scientific evidences and related inferences that indicate: (1) Sudden creation of the universe, energy, and life from nothing; (2) The insufficiency of mutation and natural selection in bringing about development of all living kinds from a single organism; (3) Changes only within fixed limits of originally created kinds of plants and animals; (4) Separate ancestry for man and apes; (5) Explanation of the earth's geology by catastrophism, including the occurrence of a worldwide flood; and (6) A relatively recent inception of the earth and living kinds.

- Arkansas Act 590


Ruse on Creation-science

• Arguing in court case that creation-science is not science.

• Defining features of a science

1. “...an empirical enterprise about the real world of sensation.” 2. “Science involves a search for order...unbroken, blind, natural

regularities (laws).”3. Explanation and prediction; use laws to make predictions and to

explain phenomena4. Testability5. Confirmation and falsifiability• Tentative, not dogmatic• Integrity


Laudan on creation-science

•Creationism does make some empirical, testable claims

•Accepted science can be resistant to change at its core.

•Creationists have modified their claims; but question is about creationism not creationists.

•Are creationist claims inexplicable? No all science can be explained through laws.

...although the verdict itself is probably to be commended, it was reached for all the wrong reasons and by a chain of argument hopelessly suspect. Indeed, the ruling rests on a host of misrepresentations of what science is and how it works.


LaudanThe core issue is not whether Creationism satisfies some undemanding and highly controversial definitions of what is scientific; the real question is whether the existing evidence provides stronger arguments for evolutionary theory than for Creationism. Once that question is settled, we will know what belongs in the classroom and what does not. Debating the scientific status of Creationism (especially when "science" is construed in such an unfortunate manner) is a red herring that diverts attention away from the issues that should concern us.


Argument by analogy

[S]uppose I found a watch upon the ground, and it should be inquired how the watch happened to be in that place, I should hardly think … that, for anything I knew, the watch might have always been there. Yet why should not this answer serve for the watch as well as for [a] stone [that happened to be lying on the ground]?… For this reason, and for no other; namely, that, if the different parts had been differently shaped from what they are, if a different size from what they are, or placed after any other manner, or in any order than that in which they are placed, either no motion at all would have been carried on in the machine, or none which would have answered the use that is now served by it (Paley 1867, 1).

Every indicator of contrivance, every manifestation of design, which existed in the watch, exists in the works of nature; with the difference, on the side of nature, of being greater and more, and that in a degree which exceeds all computation. I mean that the contrivances of nature surpass the contrivances of art, in the complexity, subtilty, and curiosity of the mechanism; and still more, if possible, do they go beyond them in number and variety; yet in a multitude of cases, are not less evidently mechanical, not less evidently contrivances, not less evidently accommodated to their end, or suited to their office, than are the most perfect productions of human ingenuity (Paley 1867, 13).


Discussion

• So how might we summarize the debate between creation-science and traditional science?

• What does the debate tell us about the nature of science?

Documents

PHI 306 Philosophy of ScienceFall 2014 - Garns Philosophy of science PHI 306 - Fall 2014