What is the soul of man? A composition of various faculties, passions, sentiments, ideas; united, indeed, into one self or person, but still distinct from each other. When it reasons, the ideas which are the parts of its discourse arrange themselves in a certain form or order, which is not preserved entire for a moment, but immediately gives place to another arrangement. New opinions, new passions, new affections, new feelings arise which continually diversify the mental scene and produce in it the greatest variety and most rapid succession imaginable.

The soul is... but an empty word, of which no one has any idea, and which an enlightened man should use only to signify the part in us that thinks...

What can be more discouraging to a man than to doubt if his soul be material, like a stone or a reptile, and subject to corruption like the vilest creatures ? And does it not prove much more strength of mind and grandeur to be able to conceive the idea of a Being superior to all other beings, by whom and for whom all things were made; of a Being absolutely perfect and pure, without beginning or end, of whom our soul is the image, and of whom, if I may say so, it is a part, because it is spiritual and immortal?

SOUL, n. A spiritual entity concerning which there hath been brave disputation. Plato held that those souls which in a previous state of existence (antedating Athens) had obtained the clearest glimpses of eternal truth entered into the bodies of persons who became philosophers. Plato himself was a philosopher. The souls that had least contemplated divine truth animated the bodies of usurpers and despots.

The soul is a compact of mind-masses combined in a most intimate and manifold manner. It grows constantly by accession of mind-masses, and upon these depend its development.

Suppose it were so; so much, then, the better, as we should not want then to show that the soul could become torpid and recover; because, then, it would never be torpid> and, consequently, would be immortal, which is all we want to prove. And this opinion, I believe, is that of the majority of thinking persons, but unfortunately mixed up with divers principles, not orthodox, some of them acknowledging a soul m man, but not in any other living being; others going one step further, and admitting a soul in other animals too, but imagining that it is a different sort of soul to that of man, instead of considering that one soul is similar to another, and that all the difference between one individual and another is corporeal,—the organization of the body or brain, by its variations, alone producing, it would appear, all the varieties of character, without any variation of soul, to which conclusion we are led by the fact that we cannot produce any thought or feeling in the mind but through the instrumentality of the body; and it seems only on the bodily organs, and physical agents upon them, that every perfection and defect of mind depends; an idiot, a philosopher, and a mouse, appearing to have quite similar souls, the difference only being in the organs of sense, which act upon the souls, and are in themselves different. No person can deny that different sensations are produced by bodily causes; why, then, must we look to something else to produce them—namely, to variations of the soul ? Bodily causes are enough, and we are not driven to seek for further causes. The soul is always, if I am correct, the same. It does not grow, it does not decay; and is as perfect in an infant as In a man—the improvement and growth of mind being only of the corporeal part.

But the reader must particularly observe, that by the word “ soul” I do not mean precisely the same thing as most persons do—the general opinion of believers in soul being that it is the spirit of the person unencumbered, and set free of the body in a more perfect state than in this life, with all the feelings and senses, and even more than when united to the body. But my meaning is very different. I look on it (as I have expressed) as a thing totally devoid of feeling or thought, excepting when it is operated on by the body, and that when not, is totally insensible, and cannot be perceived unconnected with the body by any mortal eye, but only by the Almighty.

I turned to [Aristotle's] De Anima (On Soul), expecting to get help with understanding the difference between a living human being and its corpse, relevant for the difficult task of determining whether some persons on a respirator are alive or dead. I discovered to my amazement that Aristotle has almost no interest in the difference between the living and the dead. Instead, one learns most about life and soul not, as we moderns might suspect, from the boundary conditions when an organism comes into being or passes away, but rather when the organism is at its peak, its capacious body actively at work in energetic relation to—that is, in "souling"—the world: in the activities of sensing, imagining, desiring, moving, and thinking. Even more surprising, in place of our dualistic ideas of soul as either a "ghost in the machine," invoked by some in order to save the notion of free will, or as a separate immortal entity that departs the body at the time of death, invoked by others to address the disturbing fact of apparent personal extinction, Aristotle offers a powerful and still defensible holistic idea of soul as the empowered and empowering "form of a naturally organic body." "Soul" names the unified powers of aliveness, awareness, action, and appetite that living beings all manifest.
This is not mysticism or superstition, but biological fact, albeit one that, against current prejudice, recognizes the difference between mere material and its empowering form. Consider, for example, the eye. The eye's power of sight, though it "resides in" and is inseparable from material, is not itself material. Its light-absorbing chemicals do not see the light they absorb. Like any organ, the eye has extension, takes up space, can be touched and grasped by the hand. But neither the power of the eye — sight — nor sight's activity — seeing — is extended, ­touchable, ­corporeal. Sight and seeing are powers and activities of soul, relying on the underlying materials but not reducible to them. Moreover, sight and seeing are not knowable through our objectified science, but only through lived experience. A blind neuroscientist could give precise quantitative details regarding electrical discharges in the eye produced by the stimulus of light, and a blind craftsman could with instruction fashion a good material model of the eye; but sight and seeing can be known only by one who sees.

You are easy to explain – even to you. You may call yourself a soul if that pleases you, but what you are is a nexus of electromagnetic forces, so arranged that all the interconnections and interrelationships are exactly imitative of those of your brain in your Universe-existence – down to the smallest detail. Therefore you have your capacity for thought, your memories, your personality. It still seems to you that you are you.

The human soul is a living paradox — neither a predetermined personality nor a completely open possibility. The point in this life is not simply to “become somebody,” but to become who we were each intended to be when we first entered this world. For each of us has the most to give and contributes most meaningfully when we become who we were intended to be from the beginning. That is the inside story and the hidden message that has been etched upon each soul.

Man is conscious of a universal soul within or behind his individual life, wherein, as in a firmament, the natures of Justice, Truth, Love, Freedom, arise and shine. This universal soul, he calls Reason: it is not mine, or thine, or his, but we are its; we are its property and men. And the blue sky in which the private earth is buried, the sky with its eternal calm, and full of everlasting orbs, is the type of Reason. That which, intellectually considered, we call Reason, considered in relation to nature, we call Spirit. Spirit is the Creator. Spirit hath life in itself. And man in all ages and countries, embodies it in his language, as the FATHER.

My mind is incapable of conceiving such a thing as a soul. I may be in error, and man may have a soul; but I simply do not believe it. What a soul may be is beyond my understanding.

Therefore, as a person cannot be in duplicates, it is plain, that the soul cannot be the product of mechanism. And every person knows that his self is only his self, and the same self at all times, without division, augmentation, or change of any kind, he knows it has an identity, and there* fore is not the effect of matter.

But let there be no misunderstanding: it is not that a real man, the object of knowledge, philosophical reflection or technological intervention, has been substituted for the soul, the illusion of theologians. The man described for us, whom we are invited to free, is already in himself the effect of a subjection more profound than himself. A 'soul' inhabits him and brings him to existence, which is itself a factor in the mastery that power exercises over the body. The soul is the effect and instrument of a political anatomy; the soul is the prison of the body.