Reasonableness, Common Sense, and Science

Reasonableness is not a philosopher’s term. Nowhere in philosophical literature will you find such clear-cut definitions of reasonableness as you find for the twin concept of rationality. Indeed, even on the handful of occasions on which the concept of “reasonableness” is taken up, there is hardly more than a partial characterization that can be found of its traits. What, then, does it mean to be “reasonable”? The reasonable person makes a rare appearance on the philosophical scene as a great moral character displaying in every circumstance, and especially where others are concerned, many “amiable and respectable virtues”.¹ Very little, if anything, is said about the reasonable person’s epistemic features. For example, on one place reasonable people are portrayed as having the Baconian virtues of cautious reasoning and careful consideration of evidence.² That is all. To find further insights we must turn to Rawls. Though it seems exaggerated to speak of a “theory” of reasonableness in Rawls (as Maffettone 2004 does) he is certainly the one who more than any other contemporary philosopher has made an extensive and significant use of the idea. In his work, reasonableness comes in as “an element of the idea of society as a system of fair cooperation” (Rawls 1996, 49–50) and as a “particular form of moral sensibility” (ibid., 51). Indeed, Rawls is clear in warning us that the idea of “being reasonable” which we find at the heart of his construction “is not an epistemological idea” though, he adds in parentheses, “it has epistemological elements” (ibid., 62).