The goal of this article is to reveal the primal role played by “use” in Spinoza's Ethics. Contrary to appearances, the concept is not linked only to passivity; it is an essential feature of the reinforcement of virtue toward wisdom. Considering that Laurent Bove's analyses of habit within the realm of imagination leave aside the links with adequate knowledge, this article offers an extension of his interpretation in a completely new direction. The new elements are, above all, a demonstration of (...) the place of “use” in the texts where the shift from passivity to activity is concerned, and a new interpretation of intuition in the example of the discovery of the fourth proportional number. In this example, it is argued that intuition is simply a mechanical habituation to truth, thanks to the repetition of acts of reasoning. (shrink)