Elliott Sober quotes:

The big picture, I think, is that common ancestry is evidentially prior to natural selection in Darwin's theory and in contemporary evolutionary biology as well.

"Tiger is a natural kind" and "Tiger is a historical particular" are incompatible with each other, and evolutionary biology provides a reason for favoring the latter over the former.

Creationists have long held that evolutionary theory is atheistic; defenders of the theory do the theory no favor when they agree.

I don't endorse deism or interventionist theism. My point is just that evolutionary biology is logically compatible with the former and with some versions of the latter.

Biologists now pretty universally regard vitalism as a vestige of a bygone age.

I think that the existence of Beethoven is remarkable, but I do not bristle at the suggestion that this event had a low probability given the initial state of the universe.

Trait X is fitter than trait Y in a population of organisms if those organisms have other biological traits T and live in an environment that has properties E. The theory of natural selection is filled with statements of this form.

Philosophers of biology generally recognize that evolutionary fitness (roughly, an organism's ability to survive and reproduce in its environment) is multiply realizable.

The upshot is that most philosophers of biology now hold that biological properties supervene on physical properties (where supervenience is taken to include some kind of "in virtue of" relation), and that fitness and other biological properties are not identical with physical properties.

Evolutionary game theory was originally developed as an alternative to the hypothesis of group selection; now it is clear that game theory models postulate group selection, even if they do not use the g-word.

Methodological naturalism gives advice to scientists about what they should include in their theories. There is a second type of methodological naturalism that gives advice to philosophers, which I call "methodological naturalismp." It says that the methods that philosophers should use in assessing philosophical theories are limited to the methods that scientists ought to use in assessing scientific theories.

The more evolutionary theory gets called an atheistic theory, the greater the risk that it will lose its place in public school biology courses in the United States. If the theory is thought of in this way, one should not be surprised if a judge at some point decides that teaching evolutionary theory violates the Constitutional principle of neutrality with respect to religion.

Evolutionary theory, properly understood, does not conflict with the idea that God occasionally intervenes in nature - for example, by once or twice causing a beneficial mutation to occur. Biologists have not detected any such interventions despite the data and theory they have assembled about mutation. However, I think it is a mistake to expect biological experiments to be able to detect such one-off acts of divine intervention, especially if those acts occurred in the distant past. Science isn't in that line of work.

I think that some "interventionist theisms" are compatible with evolutionary theory. (By "intervention," I don't mean that God violates laws of nature; I mean that God affects what happens in nature in ways that are additional to the ones that deism recognizes.)

Another way to test hypotheses about adaptation is to consider trait variation across a group of species instead of focusing on the trait of a single species. Rather than seeking to explain why polar bears have fur of a certain thickness, one tries to explain why bears in colder climates have thicker fur than bears in warmer climates. The former problem is hard to solve, since it is hard to say exactly what fur thickness polar bears should have if natural selection guided the evolution of that trait.

One influential philosophical position about the use of probability in science holds that probabilities are objective only if they are based on micro-physics; all other probabilities should be interpreted subjectively, as merely revealing our ignorance about physical details. I have argued against this position, contending that the objectivity of micro-physical probabilities entails the objectivity of macro-probabilities.

Darwin repeatedly used the hypothesis of common ancestry as a platform on which to build his various ideas about testing hypotheses concerning natural selection. He also argued that adaptive similarities provide little or no evidence for common ancestry. Although this second claim needs to be fine-tuned, Darwin was right that ample evidence for common ancestry can exist even if none of the characteristics we observe were caused to evolve by natural selection.

If the organisms in a species now have trait T, and this trait now helps those organisms to survive and reproduce because the trait has effect E, a natural hypothesis to consider is that T evolved in the lineage leading to those current organisms because T had effect E. This hypothesis is "natural," but it often isn't true!

Darwin and his successors have railed against the fallacy of confusing the current utility of a trait with the reason the trait evolved. For example, Darwin argued that skull sutures in mammals did not evolve because they facilitate live birth; the sutures were in place well before live birth evolved. Checking the chronological order in which different traits evolved in a lineage is one way to test an adaptive hypothesis; the fact of common ancestry is what makes that checking possible.

Just as thought experiments can't show that vitalism is true (or that it is false), they also can't show that dualism is true (or that it is false).

The indispensability argument seeks to assimilate the epistemology of metaphysical statements to the epistemology of statements that are obviously empirical. I think it fails to achieve this goal. The argument does not refute the Carnapian thesis that scientific theories and metaphysical claims differ epistemologically - observations can provide evidence for the former, but not for the latter.

From the fact that E is evidence for T and the fact that T entails M, it doesn't follow that E is evidence for M.

The indispensability argument says (roughly) that if you have ample reason to accept an empirical scientific theory that makes indispensable use of mathematics, and that theory entails that numbers exist, then you have ample reason to accept that numbers exist. The argument affirms the antecedent of this conditional, and concludes that you have ample reason to believe that numbers exist. What is striking about this argument is that it seems to show that the empirical reasons that suffice for accepting a scientific theory also suffice for accepting a metaphysical claim.

Instead of thinking of the question of race genealogically, and leaving it open whether vernacular races are genealogical units, the interest in biomedicine has been to determine whether vernacular racial categories are medically useful in diagnosis and treatment. There is on-going debate about this.

The racial categories that are used in a given society (for example, in contemporary America) are biologically meaningless, but sometimes it turns out that a vernacular racial category has biological reality.

Evolutionary biologists often avoid using the term "race" because there is so much racist baggage that comes with the term. However, they are often okay with the idea that the genealogy of human groups within our species can sometimes be inferred in much the same way as the genealogy of different species.

I disagree with the widely held view that it is metaphysical necessity, not nomological, that matters in the mind/body problem.

It can be a necessary conceptual truth that pains are painful without this ruling out the physicalist thesis that immaterial minds are impossible or the thesis that conscious states supervene on physical states. The necessity involved in these claims is nomological necessity, not metaphysical necessity (assuming that these are different).

The rabid opposition to group selection has now considerably subsided. In the process, the conceptual structure of evolutionary theory has become clearer, as have the relationships that connect different theoretical approaches.

Group selection and individual selection are just two of the selection processes that have played important roles in evolution. There also is selection within individual organisms (intragenomic conflict), and selection among multi-species communities (an idea that now is getting attention in work on the human microbiome). All four of these levels of selection find a place in multi-level selection theory.

When one theory is simpler than its competitor, this fact is relevant to saying what the world is like.

Some philosophical arguments (e.g., in connection with the mind/body problem) look pretty good, while others (e.g., those that criticize moral realism) do not.

When I was in high school I found literature and history interesting, but science not at all. Literature and history obviously involved thinking, but science seemed to be all about memorizing facts and doing mindless calculations.

Deism is logically compatible with evolutionary theory for the simple reason that the theory says nothing about the origin of the universe or of the laws of nature.

Deism claims that God creates the universe and the laws of nature and then is hands-off, with everything that subsequently happens in nature being due to natural processes.

Deism is compatible with evolutionary theory.

This is not to deny that there are versions of theism that do conflict with evolutionary biology. Young Earth Creationism is an example; it claims that God created life on earth within the past 10,000 to 50,000 years. But other types of theism are different.

I disagree with those who argue that evolutionary biology and the existence of God are incompatible.

"Methodological naturalism" and "metaphysical naturalism" are terms that often surface in the continuing battle between evolutionary biology and creationism/intelligent design. The methodological thesis says that scientific theories shouldn't postulate supernatural entities; the metaphysical thesis says that no such entities exist. In this debate, God is the supernatural entity at issue; the question isn't whether science gets to talk about mathematical entities if Platonism is correct.

Earlier attempts to show that simpler theories always have higher prior probabilities have failed, but there is a restricted circumstance in which the claim is right.

If you have evidence that C1 is a cause of E, and no evidence as to whether C2 is also a cause of E, then C1 seems to be a better explanation of E than C1&C2 is, since C1 is more parsimonious. I call the version of Ockham's razor used here "the razor of silence." The better explanation of E is silent about C2; it does not deny that C2 was a cause. The problem changes if you consider two conjunctive hypotheses.

Our own species evolved under the influence of group selection, as Darwin emphasized when he discussed the evolution of altruism.

I have spent a lot of time arguing that the theory of group selection is not the stupid, pernicious doctrine that many biologists once claimed it to be. The theory is not just conceptually coherent; there are adaptations out there in nature (like reduced virulence in some viruses) that evolved because there was group selection.

Unfortunately, philosophers of science usually regard scientific realism and scientific anti-realism as monistic doctrines. The assumption is that there is one goal of all scientific inference - finding propositions that are true, or finding propositions that are predictively accurate. In fact, there are multiple goals. Sometimes realism is the right interpretation of a scientific problem, while at other times instrumentalism is.

Scientists often seek predictively accurate models, rather than models that are true.

It is an interesting fact about model selection that the evidence at hand can indicate that a model known to be false will be more predictively accurate than a model known to be true. This opens the door to a kind of instrumentalism.

In many contexts, simplicity is not an aesthetic frill.

"Simpler is always better" is an overstatement.

Current organisms have a higher probability of sharing a single code if the common ancestry hypothesis is true than they'd have if the hypothesis of separate ancestry were true. That is, the simpler hypothesis has the higher likelihood in the technical sense of "likelihood" used in statistics.

Evolutionary biologists often appeal to parsimony when they seek to explain why organisms "match" with respect to a given trait. For example, why do almost all the organisms that are alive today on our planet use the same genetic code? If they share a common ancestor, the code could have evolved just once and then been inherited from the most recent common ancestor that present organisms share. On the other hand, if organisms in different species share no common ancestors, the code must have evolved repeatedly.

In the history and literature courses I took, epistemological questions came to interest me most. What makes one explanation of the French Revolution better than another? What makes one interpretation of "Waiting for Godot" better than another? These questions led me to philosophy and then to philosophy of science.