You see, gentlemen, reason is an excellent thing, there's no disputing that, but reason is nothing but reason and satisfies only the rational side of man's nature, while will is a manifestation of the whole life, that is, of the whole human life including reason and all the impulses. And although our life, in this manifestation of it, is often worthless, yet it is life and not simply extracting square roots. Here I, for instance, quite naturally want to live, in order to satisfy all my capacities for life, and not simply my capacity for reasoning, that is, not simply one twentieth of my capacity for life. What does reason know? Reason only knows what it has succeeded in learning (some things, perhaps, it will never learn; this is a poor comfort, but why not say so frankly?) and human nature acts as a whole, with everything that is in it, consciously or unconsciously, and, even if it goes wrong, it lives.
Fyodor Dostoyevsky, Notes from Underground, White Nights, The Dream of a Ridiculous Man, and Selections from The House of the Dead
desire, life, living, reason