  For similar reasons, arithmetic appears to be a priori. No particular experience confirms ‘2 + 2 = 4’. (Quine is not advancing what Frege derided as a ‘gingerbread and pebble’ account of arithmetic (Frege 1884, vii), in which the sentence is justified by our observations of cookies or stones.) Arithmetic is independent of any particular experience, or any easily specifiable portion of experience; hence it appears as a priori. On Quine’s account, it rests on our experience as a whole, and the fact that the theory which best accounts for that experience makes essential use of arithmetic.