אתיקה, חלק IV, משפט 23

In so far as a man is determined to an action through having inadequate ideas, he is passive (III. i.), that is (III. Deff. i., and iii.), he does something, which cannot be perceived solely through his essence, that is (by IV. Def. viii.), which does not follow from his virtue. But, in so far as he is determined for an action because he understands, he is active; that is, he does something, which is perceived through his essence alone, or which adequately follows from his virtue. Q.E.D.