The Soul is something more delicate and more difficult to treat of than either Heaven or Hell. That is why it is proper to satisfy Your Majesty’s curiosity, to speak of it a little more at length. Before saying what I desire on this subject, I will recall in a few words what the most celebrated Philosophers have thought of it.

Some have said that the Soul is a spirit or an immaterial substance; others, a kind of divinity; some, a very subtile air, and others a harmony of all parts of the body. Again, others have remarked that it is the most subtile and fine part of the blood, which is separated from it in the brain and is distributed by the nerves: so that the source of the Soul is the heart where it is produced, and the place where it performs its noblest function is the Brain, because there it is well purified from the grosser parts of the blood. These are the principal opinions which have been held concerning the Soul, but to render them more perceptible let us divide them into material and spiritual, and name the supporters of each theory that we may not err.

Pythagoras and Plato have said that the soul is spiritual, that is to say, a being capable of existence without the aid of the body, and can move itself: that all the particular souls of animals are portions of the universal soul of the world: that these portions are spiritual and immortal, and of the same nature, as we may conceive that one hundred little fires are of the same nature as the great fire at which they have been kindled.

These philosophers believed the animated universe a substance, spiritual, immortal and invisible, pursuing always that which attracts, which is the source of all movements, and of all Souls which are small particles of it. Now, as Souls are very pure, and infinitely superior to the body, they do not unite immediately, but by means of a subtile body, such as flame, or that subtile and extensive air which the vulgar take for heaven. Afterwards they take a body less subtile, then another a little more impure, and always thus by degrees, until they can unite with the sensible bodies of animals, whence (sic) they descend like into dungeons or sepulchres. The death of the body, they say, is the life of the soul wherein it was buried, and where it exercises but weakly its most beautiful functions.

Thus at the death of the body the soul comes out of its prison untrammelled by matter, and reunites with the soul of the universe, from whence it came. Thus, following this thought, all the Souls of animals are of the same nature, and the diversity of their functions comes only from the difference in the bodies that they enter.

Aristotle admits further, a universal understanding common to all beings, and which acts in regard to particular intelligences as light does in regard to the eyes; and as light makes objects visible, the universal understanding makes objects intelligible. This philosopher defines the Soul as that which makes us live, feel, think and move, but he does not say what the Being is that is the source and principle of these noble functions, and consequently we must not look to him to dispel the doubt which exists concerning the Nature of the Soul.

Dicearchus, Asclesiade (? Esculapius), and in some ways Galen, have also believed the soul to be incorporeal, but in another manner, for they have said that it is nothing more than the harmony of all parts of the body, that is to say, that which results in an exact blending and disposition of the humors and spirits. Thus, they say, health is not a part of him who is well, however it be his condition, so that, however, the soul be in the animal, it is not one of its parts, but a mutual accord of all of which it is composed. On which it is remarked that these authors believe the soul to be incorporeal, on a principle quite opposed to their intent, by saying that it is not a body, but only something inseparably attached to a body, that is to say, in good reasoning, that it is quite corporeal, since corporeality is not only that which is a body, but all which is form or accident that cannot be separated from matter.

These are the philosophers who have believed the soul incorporeal or immaterial, who, as you see, are not in accord with themselves, and consequently do not merit any belief. Let us now consider those who have avowed it to be a body.

Diogenes believed that it was formed of air, from which he has inferred the necessity of breathing, and defines it as an air which passes from the mouth through the lungs to the heart, where it is warmed, and from whence it is distributed through the entire body.

Leucippus and Democritus have claimed that it was Fire, as that element is composed of atoms which easily penetrate all parts of the body, and makes it move. Hippocrates has said that it is a composition of water and fire. Empedocles says that it includes the four elements. Epicurus believed like Democritus, that the soul is composed of fire, but he adds that in that composition there enters some air, a vapor, and another nameless substance of which is formed a very subtile spirit, which spreads through the body and and which is called the soul.

Not to shuffle, as all these philosophers have done, and to have as perfect an idea as is possible of the souls of animals, let us admit that in all, without excepting man, it is of the same nature, and has no different functions, but by reason of the diversity of organs and humors; hence we must believe what follows.

It is certain that there is in the universe a very subtile spirit, or a very delicate matter, and always in motion, the source of which is in the Sun, and the remainder is spread in all the other bodies, more or less, according to Nature or their consistency. That is the Soul of the Universe which governs and vivifies it, and of which some portion is distributed among all the parts that compose it. This Soul, and the most pure Fire which is in the universe does not burn of itself, but by the different movements that it gives to the particles of other bodies where it enters, it burns and reflects its heat. The visible fire has more of this spirit than air, the latter more than water, and the earth much less than the latter. Among the mixed bodies, plants have more than minerals, and animals more than either. To conclude, this fire being enclosed in the body, it is rendered capable of thought, and that is what is called the soul, or what is called animal spirits, which are spread in all parts of the body. Now, it is certain that this soul being of the same nature in all animals, disperses at the death of man in the same manner as in other animals, from whence it follows that what Poets and Theologians sing or preach of the other world, is a chimera which they have invented, and which they narrate for reasons that are easy to guess.