We live through myriads of seconds, but there is only one second among all these myriads which brings our whole inner world to the boil; the second in which, as Stendhal described, there suddenly takes place a crystallization in the supersaturated blood; a magical second like that of procreation, and, like it, hidden in the warm interior of one's own body, invisible, intangible, impalpable, a unique experience of mystery. No algebra of the soul can calculate it; no alchemy can divine it. Usually, even for ourselves, it remains unsearchable.