Dr Livingstone, I Presume?

Presumption is often discussed in law, less often in epistemology. Is it an attitude? If so where can we locate it within the taxonomy of epistemic attitudes? Is it a kind of belief, a judgment, an assumption or a supposition? Or is it a species of inference? There are two basic models of presumption: judgmental, as a kind of judgment, and legal, taken from the use of presumptions in law. The legal model suggests that presumption is a practical inference, whereas the judgmental model suggests that presumption is an epistemic attitude. I argue that presumption is neither a practical inference nor a merely epistemic attitude: it involves both, within the category of what we may call the inquiring attitudes.