I just read a very strange passage by Daniel Hausman. (It’s page 136 of his _Inexact and Separate Science of Economics_ if you care to check the citation.) He seems to imply that if a sentence of the form _All Fs that are C are Gs_ is to be a law, the terms all have to be semantically determinate. This isn’t because he’s an epistemicist about vagueness, and hence thinks all terms are semantically determinate. Rather it’s meant I think to be something special about laws. This is dropped in as a constraint without much by way of argument, and I didn’t understand why at all.

For example, the following looks like a law to me: _All animals that are humans have blood_. But surely _human_ is vague; it’s vague just where in the evolutionary history we went from being non-humans to humans. And if vagueness normally means semantic indeterminacy, as I think Hausman agrees, then some laws have vague terms.