"Simpler is always better" is an overstatement.

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.

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

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.

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.

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.