The basic presupposition shared by Heidegger and other philosophers in the rational-metaphysical tradition from Plato and Aristotle onwards is that the central metaphysical question is aWhy-question, and is about the reason or reasons that explain why everything is and is as it is. Metaphysicians from Plato to Hegel presupposed the most fundamental metaphysical truth to bethe answer to this question, and metaphysicians from Schopenhauer onwards presupposed the most basic metaphysical truth to bethe unanswerability of this question.

Plato’s reason for claiming that the life of the Philosopher has more pleasure than that of the Sensualist is palpably inadequate. The philosopher, he argues, has tried both kinds of pleasure, sensual as well as intellectual, and prefers the delights of philosophic life; the sensualist ought therefore to trust his decision and follow his example. But who can tell that the philosopher’s constitution is not such as to render the enjoyments of the senses, in his case, comparatively feeble?