There is hardly a philosophy which has not invoked something like the will or desire to know, the love of truth, etcetera. But, in truth, very few philosophers-apart, perhaps, from Spinoza and Schopenhauer-have accorded it more than a marginal status; as if there was no need for philosophy to say first of all what the name that it bears actually refers to. As if placing at the head of its discourse the desire to know, which it repeats in its name, was enough to justify its own existence and show-at a stroke-that it is necessary and natural: All men desire to know. Who, then, is not a philosopher, and how could philosophy not be the most necessary thing in the world?