In order to define the nature of consciousness, let us begin with an exposition and an examination of the general conception thereof elaborated and defended by the empiricist school. The thinkers belonging to this school see in consciousness a sort of stage in which data like sensations, imaginations, volitions, emotions, etc., appear and disappear. These data, which are considered to be the simplest elements of consciousness, coexist with and follow one another; they call upon and evoke each other according to the laws of association. Consciousness, then, is nothing else than a series of events occurring and taking place, a series regulated by empirical laws which one succeeds in establishing by means of induction.