Single Idea 9354

[catalogued under 12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities]

Full Idea

Why should we accept that necessities can only be known a priori? Prima facie, some necessities are known empirically; for example, that water is necessarily H2O, and that Hesperus is necessarily Phosphorus.


'Prima facie' means at first glance. See Idea 4972 for Hesperus/Phosphorus.

Gist of Idea

Why should necessities only be knowable a priori? That Hesperus is Phosporus is known empirically


Michael Devitt (There is no a Priori [2005], 2)

Book Reference

'Contemporary Debates in Epistemology', ed/tr. Steup,M/Sosa,E [Blackwell 2005], p.107

A Reaction

An important question, whatever your view. If the only thing we can know a priori is necessities, it doesn't follow that necessities can only be known a priori. It gets interesting if we say that some necessities can never be known a priori.