Philosophy of Science (phil 150)

Kuhn on the subjectivity of Theory Choice

• Believes everyone will agree that these criteria are needed • People who have different paradigms will disagree on two things: (1) How to interpret the criteria (2) How much each criteria should weigh

Constitutive and Contextual Values in Science

• Constitutive values: the source of the rules determine what constitutes acceptable science practices --Valuing simplicity, valuing that which fits with the data • Contextual values: personal, political, social, and cultural values

Bayesianism

• E incrementally confirms H iff P(H│E) > P(H) • H is absolutely confirmed given E, iff P(H│E) is "high" • P(H│E)=(P(H)P(E│H))/(P(H)P(E│H)+P(¬H)P(E│¬H) ) ○ PP(H)= probability of hypothesis § Prior ○ P(H│E)= probability of hypothesis given evidence § Posterior ○ P(E│H)=probability of evidence given the hypothesis § Likelihood ○ ¬H= not H § Given that H is wrong ○ H= hypothesis ○ E § Evidence

Principle of Sufficient Reason (PSR)

• For any fact F, there is a reason why G is the case • If reason is present then fact must be present (sufficient)

Hypothetic-Deductive (HD) Method

• Hypothetico-deductive Method ○ Have hypothesis, auxiliary hypothesis, initial conditions, and from this you deduce/confirm an observation H. F = ma I1. F = 6N I2. m = 2g A. According to the scale that I used, the mass is 2g _____ O. a = 3 m/s • HD method doesn't tell us of the value of having a variety of evidence --Mostly focuses on incremental confirmation rather than absolute confirmation

Maxwell's Argument

• If you see something with your naked eye then you are observing it Vs. • You're not observing something if you are wearing glasses Vs. • Using higher powered lens to observe something smaller How to determine observability

Law & Law Statement

• Law: regularity that holds throughout the universe, at all times and all places • Law statement: statement to the effect that such a regularity exists

Turnover Fallacy

• More turnover among false theories, not that there are more false theories than true theories at any given moment • Fallacy is in taking accumulation of all theories of past and conclude that because most theories are false in the past, then most will be false in the future Solution: look at theories from any given moment (as in chart from notes) and analyze **Lange**

Principle of Uniformity of Nature (PUN)

• Principal of Uniformity of Nature (PUN)- Nature is uniform across time and space P1. All observed F's are G P2. Nature is uniform across time and space C1. So probably, unobserved F's will be like the observed F's __________________ C2. The next F is a G

Scientific Realism/Anti-realism

• Scientific Realism: science aims to give us knowledge about both the observable and the unobservable aspects of reality • Scientific Anti-realism: science aims to give us knowledge about the desirable aspects of reality **each differs on the way in which science is conducted: Realists say that it deals both observable and unobservable, while Anti-realists say it deals only with the observable**

Scientific Revolutions, Anomalies, and Normal Science

• Scientific revolution: whenever a scientific paradigm changes; when a scientist rejects and replaces it with another ○ Accumulation of normal science • Normal science: continue doing science within the paradigm, not trying to change it, going by the (a), (b), and (c) of the paradigm; scientific work done on basis of paradigm (puzzle solving) • Anomaly: A scientific problem that makes scientists question their paradigm (Lead to scientific rev's)

Zeno's Paradox of Plurality

• Take any finite line segment and assume it is composed of an infinite number of points because you can always take a point in between any two points ○ Do points have infinite length or finite length; presumably the latter P1. All line segments are composed of infinitely many points P2. The points on the line segment have either zero or a finite length P3. If the points have a finite length L, then the segment must be infinitely long. ( L + L + L + .... = ∞ ) P4. If the points have zero length, then the line segment must have zero length . ( 0 + 0 + 0 +...= 0) C. So, any line segment would either have zero length or an infinite length --Aims to show that there could be no finite (non-zero) line segments in Euclidean geometry --Seems absurd because we have finite line segments, not just ones that are zero or infinite

Duhem's Thesis (about how theories are tested)

• Theories are tested not individually, but as a group • Therefore, theories are only falsifiable as a group • A theory T is falsifiable* iff T together with the auxiliaries A1, A2... implies some empirical predictions that could turn out to be false • If you have strange enough A's then almost any theory can be proven to be true P1. If H and A then I P2. Not I ----------------- C. Not both H and A

Invention vs. Testing Theories

**examples in lecture on childbed fever** >>Inventing and testing theories are two distinct things >>Theories can be invented without purposes for being tested ex. A theory may come to you/be invented in your dreams or while you're dozing off. This has nothing to do with purposes for testing that theory. You can test it, but you don't have to.

Critiques of HD-method, concerning alternative/statistical hypothesis

1. Most scientific research uses inductive reasoning rather than deductive a. statistical evidence 2. Observational predictions cannot be deduced Ex. H. Smoking while pregnant increases the risk of birth defects I1. Group 1 smokes while pregnant I2. Group 2 doesn't smoke while pregnant ______________________ O. More birth defects in Group 1 • Cannot deduce this because group 2 could have gotten lucky or have certain genetic features that protect better from passing on birth defects due to smoking. Some people may have not smoked their whole life etc. • Statistical hypotheses rely on possibilities and therefore cannot be used to deduce an observation. The HD-method does not account for these types of hypotheses **Salmon**

Laws of Nature

1. Universal Generalization (All A are B or No A are B) 2. Support counterfactuals (conditional statements whose antecedents are false) 3. Support Modal Statements (statements of physical necessity and impossibility)

Kuhn on Nature of Scientific Rationality

A choice can be rational even if it appeals to subjective reasoning • Rationality does not have to be independent of value individual value judgments P1. Scientific theory-choice necessarily depends on subjective value judgments (inherent in scientists paradigms) P2. Scientific theory-choice is rational C. So, theory-choice based on subjective value judgments can be rational • So, two people can each make rational choices in picking a paradigm and end up not choosing the same one • People who object theories are not irrational because they chose to do so ○ Each persona is being rational to the standards that they accept **Duck/Rabbit Theory**

Paradigms

A set of (a) fundamental theoretical assumptions, (b) solutions to intriguing scientific problems, and (c) values that determine what counts as important problem s and how to go about solving them

Desiderata for better/worse explanations (on causal model)

Desiderata (desired things) Good Explanation • Explanatory information has to be relevant Bad Explanation • Stale news

Absolute and Incremental Confirmation

Absolute Conformation --H is absolutely confirmed (given E: evidence) iff it is reasonable to accept H (given E) Incremental Conformation --H is incrementally confirmed by E iff it is more reasonable to accept H with E than without E

Falsifiability

Ability to be tested/proven false

Nicod's Criterion

Any hypothesis of the form "All F's are G" is incrementally confirmed by an F that is G (i.e. by a positive inference).

Deductive Validity and Soundness

DV: if premises are logically true then conclusions must be true. Soundness: An argument is sound iff (1) it is valid and (2) the premises are actually all true

IBE and Enumerative Induction

Basic Induction: inference from observed regularity to a universal regularity or regularity in the next instance --All enumerative inductions are IBE --there are IBE that are not enumerative inductions **Harman**

Why do Baysians think that any agents' degrees of belief should follow the four rules developed by the Russian mathematician Kolmogorov as axioms for the probability calculus?

Because if you don't follow these axioms, you will be willing to accept bets which guarantee that you will lose, no matter what happens.

Black's response to the Achilles Problem

Black is trying to show that the way we think of distances as being able to be divided an infinitely number of times is wrong and needs to be rejected. Showing through example of marbles

Black's argument against possibility of performing an infinite # of tasks in a finite time

Black thinks this is not the correct solution, he thinks P1 is false --He thinks that A does not have to complete an infinite number of acts in a finite time --He thinks it's incoherent to even think about completing an infinite number of task

According the HD-method of confirmation, how is a hypothesis confirmed?

By showing that it deductively follows from some observations

Paradoxes

Conclusion of a problem seems both acceptable and unacceptable

Explanans & Explananda

Explanans: what does the explaining (premises) Explanandum: what is to be explained (conclusion)

Criteria for better explanations (explanatory virtues)

Explanatory Scope: Better to explain more facts Simplicity: Better to have a less complex explanation Not ad hoc: not overly complicated

True or False: According to Black, the idea of a machine that transfers a marble an infinite number of times in a finite period involves no contradiction.

False

True or False: According to the HD-method, theories are proved to be true by their observational consequences.

False

True or False: All scientific explanations aim to account for unfamiliar or puzzling things in terms of ordinary, familiar things.

False

True or False: Demonstrative reasoning concerns matters of fact.

False

True or False: Every truth to the effect that whenever and wherever conditions of a specified kind F occur, then so will certain conditions of another kind, G, is a law of nature.

False

True or False: Hume thinks that it is a relation between ideas that the future will resemble the past.

False

True or False: Theories that make risky predictions about what will be observed are unscientific

False

True or False: Cartwright argues that if no law covers some event, then there can be no explanation of the event

False; She believes that all events do not occur because of laws

Duhem's Critique of Falsificationism

Falsification is ambiguous because theories can only be falsified as a group and not independent of one another

Hempel's Raven Paradox (Paradox of Confirmation)

H: All ravens are black I: This thing is a raven ------ O: This thing is black Paradoxical Conclusion: Any non-black, non-raven confirms "All ravens are black"

Contrapositives

H: If p then q Contrapositive of H: If not q, then not p

What requirement for a scientific explanation is lacking in Hemple's example of Francesco Sizi's bogus explanation of the number of planets ("there are seven windows in the head...")?

Hemple's requirement of explanatory relevance

Problem of Demarcation

How to distinguish between science and non-science; especially between pseudoscience and science **Popper**

The Idea of Value-Free Science

Idea that contextual values play no role in the interworking's of scientific inquiry

Equivalence Condition

If H and K are logically equivalent, then E (evidence) confirms H iff E confirms K. (where H and K are two hypotheses essentially saying the same thing) --Anything that confirms one confirms the other

The Principle of Identity of Indiscernables (PII)

If two things are exactly alike in which no difference between them, then they are indecernible and therefore the same

Inductive Strength

Improbable to have true premises and false conclusion (strong). Not improbable to have true premises and false conclusion (weak)

Duhem in analyzing results from an experiment

In reporting the result of an experiment, one must take for granted many theories on which the interpretation is based

Inference to the Best Explanation (IBE)

It is reasonable to accept H on the basis of E iff H is the best available explanation for E

Ceteris paribus Laws/Generalizations

Laws/generalizations that lack empirically testable content Only hold under certain conditions

Matters of Fact and Relations of Ideas

Matter of Fact: Something that can be proven false (Hume) --Relation between Cause and Effect can only be known by experience Relation of Ideas: truths that hold independently of experience. ex: 2+2=4. This is true whether you are familiar with mathematics or not.

Causal Chains/Histories

Never-ending chain of causal histories. • Never be able to come up with a complete causal history because you may leave out intermediate steps • And there are things we don't know of because they fall out of our "backward light cone" ○ Some events are just unknowable to us

What does Ruse mean by insisting that science is tentative?

No accepted theory is ever guaranteed for certain to be true

Falsificationism

Objective of science is to solve problems. Therefore, any other statement or theory outside the realm of scientific investigation is meaningless

Observable vs. Unobservable Entities

Observability is relative. P1. Someone with zero hairs on their head is bald P2. Someone with one hair on their head is bald _________________________ C1. Someone with two hairs is bald. C2. Someone with n number of hairs is bald --Indeterminate case

Arguments

Ordered set of sentences in which the last set are conclusions and are meant to be supported by the previous set which are the premises of the argument

Longino's Argument against the Idea of value-free science

P1. All theories are underdetermined by the available data. C1. So, since scientists do accept theories, they must have some reason(s) other than how well theories fit the evidence to prefer one theory to another P2. Sometimes, these other reasons are determined by contextual values. C2. So, sometimes scientific theory choice is determined by contextual values **this argument is a version of the undetermination argument**

Cartwright's argument against DN-model

P1. At least some scientific explanations (essentially) invoke ceteris peribus laws P2. Ceteris peribus laws are not true (descriptions) C. Some scientific explanations invoke things that are not true (as descriptions)

The Pragmatic Justification of Induction

P1. Either PUN is true or it is false P2. If it is true then inductive reasoning will most successfully predict the future P3. If it is false then no method will predict the future P4. Our goal is to predict the future ______________ C. So, by using inductive reasoning, we will come as close to achieving our goal as possible.

Underdetermination Argument

P1. For any theory T (about unobservables) and any evidence E, there is an incompatible theory T* that fits E just as well as T P2. If one's evidence fits two incompatible theories equally well, then one does not know either theory to be true. C. No theory (about unobservables) can be known to be true.

Underconsideration Argument

P1. For most currently accepted theories (about unobservables) there are incompatible, but unconsidered theories that one has at least as much reason of any sort (evidence or explanatory virtues; simplicity and ad hoc-ness) to believe P2. If one has at least as much reason to believe T* as one has to believe T, then one does not know T. C. Most currently accepted theories (about unobservables) are not known

No-Miracles Argument

P1. It would be a miracle if empirically successful theories were not correct about the unobservable aspects of reality P2. There are probably very few or no miracles ______________________ C. So, probably most or all empirically successful theories are correct about the unobservable aspects **Va Fraussan**

Argument from PSR

P1. PSR P2. There is no reason why the objects in the universe (holding fixed their spatial relations) would be located at some particular point in absolute space rather than another C1. So, objects cannot be located at any particular point rather than another P3. But, if there is absolute space, then objects must be located at some point in absolute space C2. So, there cannot be absolute space

Newcomb's Problem

Problem of choosing money from two boxes. Box A transparent ($10k), box B opaque ($1M). Choose both or only B. Machine has predicted what you would pick w/99% accuracy. Do you keep your same choice or switch. >>Rational Choice/Dominance: If option 1 is better than option 2 in some possible circumstances and 1 is never worse than 2 in any possible circumstance then it is rational to choose option 1.

Hume's Problem of Induction

Problem of how to justify PUN • Every time you make an inductive inference, you are assuming this (PUN) to be true • Hard to argue anything using Hume's logic because in order to have a strong argument, you have to have premises and assume that certain topics are true before you draw your conclusion --problem is that you can't justify making assumptions • Circular argument, thus, PUN cannot be justified

Ruse and Laudan (criteria for a theory to count as scientific)

Ruse: 1. Falsifiability Some possible observation would disprove the theory 2. Tentative The theory could be rejected (in the right circumstances) 3. Testable The theory makes some empirical predictions 4. Law-governedness The truth of the theory can be explained by some natural laws Laudan:

Incommensurability of Standards (across paradigms)

Scientists upholding different paradigms may agree on certain broadly defined desiderata for theories (**accuracy, consistency, simplicity, explanatory scope, fertility**), but they typically disagree on their application.

Pessimistic Induction

Should immediately reject theories now because in the future our current theories will likely be proven to be false (anti) P1. Most of the theories accepted in the past are incorrect about the unobservables ________________ C. Probably, most of the theories we are currently accepting are also incorrect about unobservables **Lange**

Absolute Space

Space can exist by itself as its own entity without presence of material objects

Absolutism about Space

Space is a thing (substance), called 'absolute space'---a sort of container into which all material things are placed Space is infinite in all directions, space is isotropic, is independent for its existence of any material thing **Newton/later Clark**

Standard solution to Achilles Paradox (according to Black)

Standard way to approach the problem is to reject premise 2 ("it is impossible to complete an infinite number of tasks in a finite time") because it is possible to complete some amount of infinite tasks in a finite time

What does Laudan believe to be science's strongest argument against creationism?

That creationism makes false empirical predictions.

What does Cartwright mean by saying that "God may have written just a few laws and grown tired"?

That there may not be laws of nature governing everything that happens

True or False: According to Cartwright, ceteris paribus laws can figure in scientific explanations.

True

True or False: According to Lewis, all explanations provide information about causal histories

True

True or False: According to Ruse, any proposed explanation of our observations in terms of a Creator intervening by supernatural processes

True

True or False: According to the Subjectivist interpretation of probability, the probability of a hypothesis is the degree of belief that an agent has in that hypothesis

True

True or False: The 'pessimistic induction' grants that past scientific theories were supported by evidence roughly as compelling as the evidence for current scientific theories.

True

True or False: The HD-method accommodates Duhem's point that many scientific theories do not by themselves (i.e. without auxiliaries) have any observational consequences.

True

True or False: Black thinks that the real difficulty with Zeno's Achilles paradox concerns the fact that if Achilles is to overtake the tortoise, he must perform an infinite number of acts.

True; to Black the concept of this supertask is incoherent

Zeno's Achilles Paradox

Turtle gets 100m head start on Achilles P1. If Achilles is to overcome the tortoise, then he must complete an infinite number of acts in a finite time (super task) P2. It is impossible to complete an infinite number of tasks in a finite time. C. Achilles cannot overcome the tortoise

The Bucket Argument

W1: Bucket with level water; W2: Bucket with water curvature --If relationism is true, there is no way to distinguish between the effects of the water in bucket 1 and the water in bucket 2 P1. The difference between world 1 and 2 can be explained by the fact that the bucket is rotating relative to absolute space in world 2, but not in world 1 P2. The difference between world 1 and 2 cannot be explained in terms of the bucket rotating relative to any other material objects because there are no other material objects. P3. But the difference can only plausibly be explained by the rotation of the bucket C. So, the difference between world 1 and 2 can only be explained if there is absolute space

Argument from PII

W1: is located at a fixed point in space; W2: visually identical to W1, but shifted to left 5 meters P1. If Newton's absolutism is correct, P2. W1 and 2 are indecernible P3. PII C1. W 1 and 2 are not distinct C2. Newton's absolutism is not correct

What was the main question that Popper sought to answer?

What is the difference between science and psuedo-science

According to Black, what question arises from the argument behind the so-called Achilles paradox?

Which mistake is made in the argument

Narrow Inductivism

idea of how we come to discover hypotheses 1. Gather all the relevant evidence 2. Analyze evidence 3. Come up w/a hypothesis that fits the evidence 4. Test hypothesis - Evidence justifies theory - Sometimes they feed off of each other in a loop --Hemple says that this (narrow inductivism) is not true and that evidence is only gathered once you have a theory, even if it is a vague one. Science does not

Aristotle's solution to the Dichotomy

• While it is impossible to run an infinite distance in a finite time, it is possible to run an infinite number of finite parts of a finite distance • Difference between having an infinite number of parts and being infinitely big (the number 2 can be divided into infinitely many parts, but it is not infinitely big) • This solution is not accepted because it requires that there be infinitely many time intervals and is thus counter-intuitive.

A priori and a posteriori arguments for PUN

• a priori (not appealing to experience), such as mathematical truths ○ Can't use this because world can be full of these ○ Meaning that you don't have to know mathematics for it to hold true in nature, so there could be a priori arguments in nature without our knowing • argument or an a posteriori (appealing to experience) ○ Experience confirms past, but cannot really use this to justify tomorrow because you haven't experienced all of nature can't use either

Zeno's Dochotomy Paradox

○ According to the way we define space (and time), it should be possible to continuously divide any distance in half ○ But this would mean that you would not be able to travel the full distance ○ Experience and common sense tell us that of course you can travel the full distance and beyond even ○ Based on the idea that it is impossible to travel an infinite number of finite distances in a finite time

DN-model of Scientific Explanations (known as "covering-law model")

○ Explanation is a sub-category of an argument ○ Explanations: Arguments that satisfies 4 conditions: 1. Argument is valid (explanandum is valid) 2. Premises are true (explanans are true) 3. A law occurs among premises (explanans contains law of nature) 4. Conclusion is empirical fact (explanandum is empirical fact) **Hempel**

Lewis's Causal Model of Sci. Explanations

○ Need causal history to explain a cause (not all of it because there is a never-ending chain of causal histories, but enough of it's history) ○ What is a good/bad explanation? --Depends on what you were looking for --How well you explain it ○ C causes E iff (C=cause, E=effect) ○ If C were to occur, then E would occur ○ If C were not to occur, then E would not occur

Relationalism about Space

○ No such thing as absolute space ○ Space only exists as a relation between material things; if no things, no space ○ Space is a collection of spatial relations between material things (above, below, in between, etc.) **Leibniz**