Chapter 2

Classification of the proofs of the simplicity of the soul

431. The proofs with which the simplicity of the soul can be demonstrated are usefully reduced to three great classes. They are derived:

1. from consciousness;

2. from the special properties of the soul springing from consciousness;

3. from the soul's activities, that is, from the need to presuppose the simplicity of the soul in order to provide a sufficient reason, or necessary explanation, of these activities.