It Is The Mark Of An

This popular formulation does not appear in Aristotle's surviving works. It likely derives from a misreading of Nicomachean Ethics 1094b24, where Aristotle actually argues that an educated person should expect only the degree of precision a subject allows. The modern phrasing first appeared in Lowell Bennion's Religion and the Pursuit of Truth (1959) and was subsequently attributed to Aristotle.