Chapter 1

The principle to be used in classifying the opinions
of the ancients about the nature of the soul

4. First, let me explain how I arrived at my guiding principle in classifying the different opinions which the ancients professed about the nature of the human soul. Things composing the universe are joined like links in a chain. The first link is matter; the second, the sensitive soul which feels and perceives matter; the third, the intellective soul which perceives feeling; the fourth, being which shines in the intellective soul and serves as a universal means of knowledge; the fifth, God who is absolute being itself, the first and supreme origin of everything else I have mentioned.

5. The whole universe is suspended from heaven by this chain whose middle link is the intellective soul, joined to the first two links through sense and to the second two through the idea and the influence of the subsistent Ens, where idea has its seat and everlasting dwelling place.

6. Now there is no doubt that those who first asked themselves about the nature of the soul turned their attention and curiosity to the intellective soul. The person who decides to reflect on self can begin only from myself (Psychology [Essence of the Human Soul], 69-70), in which the intellective soul is already contained.

As I said, however, the soul is linked on one side with matter and sense, and on the other with the idea and with God. Moreover, it is incapable of making distinctions unless the mind is already trained to concentrate and observe analytically. This takes time, and was lacking in the first thinkers. Consequently, the concept of the soul was confused in their minds with one or other of these four things which, although not the soul, are intimately connected to it. Four classes of erroneous systems about the soul would have been expected, and this was in fact what occurred. These systems referred the nature of the soul either to matter, or to sense, or to the idea or to God himself.

7. We can separate and isolate what is true in these erroneous systems if we remember that their authors were acute observers of what is bound up with the soul, and that truth is found in their observations. On the other hand, since they did not notice that the things they observed were not the soul which they intended to define, their inattention gave rise to falsity. The fount of all their errors was their failure to observe the differences separating the soul from what is joined to it. This is quite normal: the human mind first apprehends all things together, and then distinguishes them.