Attention (prosoche) is the fundamental Stoic spiritual attitude. It is a continuous vigilance and presence of mind, self consciousness which never sleeps, and a constant tension of the spirit. Thanks to this attitude, the philosopher is fully aware of what he does at each instant, and he wills his actions fully. Thanks to his spiritual vigilance, the Stoic always has “at hand” (procheiron) the fundamental rule of life: that is, the distinction between what depends on us and what docs not. As in Epicureanism, so for Stoicism: it is essential that the adepts be supplied with a fundamental principle which is formidable in a few words, and extremely clear and simple, precisely so that it may remain easily accessible to the mind, and be applicable with the sureness and constancy of a reflex. “You must not separate yourself from these general principles; don’t sleep, eat, drink, or converse with other men without them.” It is this vigilance of the spirit which lets us apply the fundamental rule to each of life’s particular situations, and always to do what we do “appropriately.” We could also define this attitude as “concentration on the present moment”.