The consciousness of our existence being composed, then, not only of our actual sensations, but of the train of ideas which gave rise to the comparison of our sensations, and of our past existences, it is evident that the more ideas we have, the more certain we are of our existence; that the more we have of intellectual capacity, the more we exist; that it is by the power of reflection alone that we are certain of our past existence, and view our future one; the idea of futurity being nothing more than a comparison of the present with the past inverted, since in this light the present is past, and the future present. This power of reflection being denied to animals, it is certain they cannot form ideas, and consequently their consciousness of existence is less sure, and less extensive than ours. Having no idea of time, no knowledge of the past, nor conception of the future, their consciousness of existence is simple, depends solely on the sensations which actually affect them, and consists in the internal sentiment which these sensations produce. May we not conceive what this consciousness of existence is in animals, by reflecting on our own state when strongly occupied with some object, or violently agitated by some passion, which banishes every reflection upon self? This state we familiarly express by saying, the man is absent or beside himself; and people are in reality beside themselves, when they are occupied with sensations actually present to them, especially if those sensations are so violent and rapid as to allow the mind no time for reflection. When thus situated we feel pleasure and pain in all their varieties; therefore, though seemingly without the participation of the mind, we have a consciousness of our existence. This state, to which we are occasionally exposed, is the habitual state of animals; deprived of ideas, and furnished with sensations, they _know_ not their existence but _feel_ it. To render more sensible this difference, let us consider minutely the faculties of brutes, and compare them with the actions of man. Like us they have senses, and receive impressions from exterior objects; they have also an interior sense, an organ which retains the agitations occasioned by those impressions, and consequently sensations which, like ours, are renewable, and are more or less strong and durable. But they have neither ingenuity, understanding, nor memory; because they are denied the power of comparing their sensations, and because these three faculties of the mind depend on this power.