The Meaning of Kind Wit Conscience, Conscience, and Reason in the First Vision of Piers Plowman.
Kind Wit is an understanding that is in man naturally, rather than by reasoning; it is the natural understanding of first principles of both the speculative and practical intellect, which serves as the source of the knowledge that Conscience applies to a particular act. As the application of knowledge to act, it is distinguished by Aquinas from synderesis (ST 1 a, 79.13). Unlike synderesis, conscience is fallible. Reason, to WL a ruler and counsellor, stands not for the faculty of intellect but rather for the intellectual virtue of prudence or practical wisdom.
MP 84 (1987): 351-58.