Chapter 1

The unity of the soul in each human being

125. We have to draw all our positive teaching about the soul from meditation on myself. I shall begin immediately by showing that the soul is one in each human being because each is never more than one myself.

126. This direct, clear demonstration of the unity of the soul disposes of the error requiring simultaneously three souls, animal, sensitive and intellective, which certain authors have endeavoured to posit in human beings. A similar mistake is made by those who posited two souls, one sensitive, one intellective. The source of the errors is clear; these philosophers have always sought the kind of soul present in myself, but not where it actually is. Even granted the existence in human beings of a principle of vegetation and sensation distinct from myself (which could easily be the case), this principle would not be the human soul, but something different from it. It is indeed obvious that the soul is one - as obvious as it is to each person that he is a single human being, not two or more. This is evident because consciousness tells him so, and consciousness is precisely the perception of the soul, or includes it. It is, therefore, a unique witness worthy of faith, and infallible in this argument. Later, I shall answer several objections which could be made against this truth.