Meeting 12: Biological Laws (4/15)

Reading:

• Beatty, “The Evolutionary Contingency Thesis” [CIEB §11]
• Sober, “Two Outbreaks of Lawlessness in the Philosophy of Biology” [CIEB §12]
• Lange, “Are There Laws About Particular Species?” [PDF]

Presentation:
Cameron | Brian commenting

One of the more recalcitrant issues in the philosophy of biology, to my mind, concerns the existence of biological laws. Now, one might well wish to dismiss this debate as unimportant. While it used to be the case that a science was legitimized by the identification of laws, this view has fallen out of favor. Philosophers have gradually come to accept that biology is an important science, whether or not it has laws. As Dupré remarks in his Disorder of Things, “biology is surely the science that addresses much of what is of greatest concern to us biological beings, and if it cannot serve as a paradigm for science, then science is a far less interesting undertaking than is generally supposed” (Dupré 1993, 1). This of course leaves open the issue of whether there are laws in biology: it just emphasizes that biology’s status as a legitimate science doesn’t turn on it.

What are natural laws in general — in, say, physics? This is also a vexed question. Early on, the logical positivists wanted to make sense of laws’ necessity by virtue of something syntactic. But this clearly fails when we consider pairs of syntactically isomorphic propositions like (1) and (2) mentioned by Beatty (CIEB, 221). Something’s being a law thus must have something to do with its content. But what? Laws are necessary truths, but they seem not to be as necessary as broadly logical truths. There’s no inconsistency in the proposition that electrons have a charge of π coulombs. Not so for the claim that some bachelor is married. But then, laws seem to have more necessity than run of the mill contingent truths (like the proposition that every coin in my pocket is made of copper). This perplexing “intermediate” sort of necessity has proved extremely difficult to capture rigorously.

Whatever laws are, it is generally agreed that they possess some degree of necessity and (perhaps because of this) support counterfactuals (claims about what would have been the case, had something else occurred). Here is where Beatty’s expansion of Gould’s evolutionary contingency thesis seems relevant! If facts about biology are “highly contingent”, as Beatty supposes, then it seems that there cannot be genuine biological laws. Perhaps there might be natural laws that in a sense overlap biology (the Hardy-Weinberg “law”, for example?), but these are not distinctively biological.

Lange believes this claim to be too hasty. Perhaps we are being too demanding to require that laws be exceptionless regularities (propositions of the form ‘All Ps are Q’, with no exceptions). As Nancy Cartwright has argued in the past, it may be that even presumably paradigmatic physical laws hold at best ceteris paribus. Be that as it may, biologists evidently have in mind something other than strictly universal generalizations when they say things like ‘the robin’s egg is greenish-blue’. These claims seem to play the role of laws. Indeed, Lange believes that a close look at what role they play in biology might help illuminate what laws are in general.

For more background on the philosophical debates about natural laws, I recommend this entry in the SEP by John Carroll.

Study Questions

• Why does Beatty believe that biological generalizations describe evolutionary outcomes? What does this mean?
• Beatty identifies a weak and strong sense of evolutionary contingency. What is the difference? How do these compare to Gould’s thesis?
• We might identify an argument-from-cartoon in Beatty’s paper (232-3). How might that argument go?
• Why does Lange believe that attempts to circumscribe natural laws by reference to “local predicates” fails?
• How does a claim like ‘The S is T’ differ from the claim ‘All Ss are T’?
• Why is it problematic to construe claims like ‘The S is T’ as ascriptions of T-ness to healthy Ss?
• Beatty speaks at one point of “frozen accidents”. How could Lange put this notion to work?
• How might Lange respond to Beatty’s “Evolutionary Contingency Thesis”?