As I pointed out in the Introduction, philosophers of science have often concentrated their attention on the physical sciences. Often, indeed, the physical sciences have been taken to be examples of what a good science should be. For example, Popper illustrated his falsificationist criterion for separating the scientific sheep from the pseudo-scientific goats by taking Einstein's theory of relativity as a clear example of a sheep. One feature that is often held to distinguish the physical sciences is their possession of strict, exceptionless, mathematical laws (or, as some prefer to call them, simply “laws”). The speed of light is a strict mathematical constant, and the atomic numbers of chemical elements are exact numerical values. Sciences that lack such laws, such as meteorology or economics, are often relegated to the inferior status of “special sciences”. The main focus of this chapter will be on the features of biology that make it different from the allegedly exemplary physical sciences. Recall my earlier quotation from Dawkins to the effect that biology is a more unified science than physics. I shall argue that, when we examine what the unifying feature actually is, we can see that biology is more than a “special science”. In some ways it is exemplary.

Lawlessness in biology

There is reason to think that, like the special sciences mentioned above, biology does not have strict mathematical laws of its own. Th ere are, as in any science, generalizations. But these generalizations have a habit of proving to be: (i) not distinctive to biology; (ii) not strict, exceptionless, mathematical laws; or (iii) not laws at all. That is, put in more positive terms, the generalizations found in biology are: (i) laws that belong to other sciences; (ii) ceteris paribus laws; or (iii) true by definition.