 Conscience in Aquinas’ view is not a special power or presence within us, but is our practical intelligence at work, primarily in the form of a stock of judgments about the reasonableness (rightness) or unreasonableness (wrongness) of kinds of action (kinds of option). Since each such judgment is of the form “[It is true that] action of the kind phi is always [or generally] wrong [or: is generally to be done, etc.]” or “phi is [always] [or: generally] required [or forbidden] by reason”, it must be the case – as Aquinas stresses very forcefully – that one’s conscience is binding upon oneself even when it is utterly mistaken and directs or licenses awful misdeeds. For since it is logically impossible that one could be aware that one’s present judgment of conscience is mistaken, setting oneself against one’s own firm judgment of conscience is setting oneself against the goods of truth and reasonableness, and that cannot fail to be wrong: ST I-II q. 19 a. 5; Ver. q. 17 a. 4. The fact that, if one has formed one’s judgment corruptly, one will also be acting wrongly if one follows it (ST I-II q. 19 a. 6) does not affect the obligatoriness (for oneself) of one’s conscience. This teaching about conscience was rather novel in his day and to this day is often misrepresented or misapplied as a kind of relativism or subjectivism. But it is actually an implication of Aquinas’ clarity about the implications of regarding moral judgments as true (or false) and of thus rejecting subjectivism and relativism.