Pythagoras and Plato have both maintained the doctrine that the soul was immaterial in its nature; that is, a being existing without aid from the body, and capable of action uncontrolled by any thing corporeal. They hold that all the individual spirits of animals were emanations from the universal Soul of the World, and that these off-givings were incorporeal, immortal, and of the same nature as the pervading Essence itself. They illustrated their doctrine well, by the analogy of a thousand little lights which are all of the same nature as the great flame at which they were kindled.
§ 4.
These philosophers believed that the universe was animated by an immaterial Essence, immortal and invisible, knowing everything, and acting always; and which is the cause of every movement, and the origin of all spirits, these being merely emanations from it. Then, as spirits are very subtle, they cannot unite (they observe) unless they can find a body subtle as the light, or as that expanded air which the vulgar take for heaven. They therefore assume a body less subtle, then another somewhat gross; and thus by degrees they come to be enabled to unite themselves to the bodies of animals, into which they descend as into dungeons or sepulchres. The death of the body, according to them, is the life of the soul, which was in a manner buried, and could only in a feeble way exercise its noblest functions. At the death of the body, the soul shakes off materiality, comes forth of its prison-house, and unites itself to the Soul of the World from which it emanated.
According to this opinion then, all the spirits of animals are of the same nature; and the diversity of their functions and faculties arises solely from the difference of the bodies into which they descend.
Aristotle supposes an universal intelligence, acting on particular intelligences, as light acts upon the eye; and that as light renders objects visible, so does this universal intelligence render the others intelligent.
This philosopher defines the soul as that whereby we live, feel, think, and move; but he is unsatisfactory as to the nature of that Being which is the source of its noblest functions. It is needless, therefore, to search in his writings for a solution of the difficulties which exist upon this subject.
Dicearchus, Asclepiades, and Galienus, have also, to a certain extent, believed that the soul was immaterial, but in a different way from that already alluded to. They suppose that the soul is nothing else than the harmony of all the parts of the body: that is, the result of an exact blending of its elements and disposition of its parts, its humours, and its essences. Thus, they say, as health is not a part of that which is healthy, although it is connected with it, so neither is the soul a part of the animal, although it be within it, but simply the harmony of all those parts which go to form the containing body.
On these opinions we must, remark, that their defenders believe in the immateriality of the soul on self-contradictory principles; for to maintain that, the soul is not a body, but merely something inseparably attached to a body, is to say that it is corporeal. We not only term that corporeal which is a body, but everything which has form and accident, and which cannot be separated from matter.
Such are the opinions of those philosophers who maintain that the soul is incorporeal or immaterial. We see that they are discordant and contradictory to each other, and consequently little to be heeded as points of faith. We now come to the opposite party, who have upheld the doctrine of its materiality.