All Gnosticism presupposes that the afferent & apprehent subject of experience is a thing disparate from its body categorically. It presupposes that the mind is an utterly different sort of thing than the body, and than other bodies. The presupposition is quite natural: I persist from one moment to the next, despite the adventures of my body. Indeed, I persist even when large bits of my body are amputated. I’ve lost a hand; yet, here am I, nonetheless. My body is diminished, but I am by this not much diminished in and as myself.
This basic Gnostic presupposition is then not wholly unreasonable. But, it is not reasonable enough.
For, it must struggle with the obstinate fact that the mind suffers changes to the body, and vice versa; that, indeed, the mind suffers changes to the body as changes to itself, and vice versa. There seem to be no good ways to resolve that struggle in favor of the Gnostic presupposition. Philosophers have been trying to resolve it for 4,000 years, and … nothing.
Easier then, and beneficial withal, as tending to greater phronetic sagacity and prosperity, to suppose per contra with Aristotle and with the Church – with, that is to say, God Almighty, whose body and mind together is (the singular is here deployed advisedly) the Church – that the mind and body are a single integral entity of various aspects, parts, participations, and so forth.
All Gnosticism hangs upon a fundamental error about human being, that has been generalized to creaturely being per se.
This basic mistake queers all modernity; lots of antiquity, too.
Sad. So much ink, thought, and blood have been spilt in service of that error. 50 million lives in the 20th century alone, almost none of whom had any idea that they were in their torments suffering the sequelae of the basic Gnostic error. Sad.
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NB: this is why it is so crucial to get metaphysics right; which is to say that it is crucial to get the terms of metaphysical discourse (and for that matter of all other discursive disciplines) nailed down properly. A moment of weakness in intellectual rigor can lead to disaster for millions.
The Orthosphere 
>This basic mistake queers all modernity; lots of antiquity, too.
Wait, what? Modernity tends to err towards too much materialism, not too much idealism, towards the idea that the mind is just the body i.e. the brain and nothing more.
And if the 50 millions are the victims of Communism and Nazism, I think they were very clearly the victims of too much materialism, victims of the idea that there is nothing more to humans than their bodies, and hence there are no moral reasons to treat them any better than animals.
Indeed, this is one of the great and sad ironies of modernity. Everybody, even the saner liberals think a man is inherently more valuable and has a moral claim to better treatment than a mouse. But on a purely materialistic basis it is impossible to tell what exactly is the difference between a man and a mouse. A man is someone who uses tools? Some monkeys do use sticks as tools. A man is someone who recognizes himself in a mirror? Elephants can do that.
With much sympathy to what you have here said, I would suggest rather that the peculiar and characteristic modern hatred of human bodies – so that modernists are not too troubled in principle (but only rather adventitiously, so that if need be they may participate) by holocausts of millions, or then by their own participation therein – is due at bottom to a derogation of the material in favor of something else – even when that something else is likewise derogated, as is the case with modernist materialism, which hates matter just as much as it hates all other sorts of things, such as those of the spirit.
Modern materialism hates worldly reality, in both its material and its spiritual aspects. It reduces the spiritual to the material, then hates the material for its deficient spirituality. Whatever its focus at this or that time, the Gnostic impulse is to a hatred of reality as we find that she actually is. It is perhaps not too far a stretch to suggest that hatred per se – animosity to fact per se – is essentially Gnostic. All the classical Gnostic sects – and their offshoots in Catharism, e.g. – felt the same way. They wanted above all to escape from embodied reality; from actual fact. They hated what it is like to be human.
To them, the entire shooting match of worldly life – of, that is to say, properly human life – was from the bottom up abhorrent.
The basic Gnostic move then is to protest against actuality, in favor of some imaginary ideal. Not to pick on Gnostics, to be sure; such protests are endemic among humans, so that we get such things as Greek tragedy, in which the natural human protest against the real is reconciled at the last with the real. But still, in the integral cultural life of ancient Greece, the tragic reconciliation at the end of the trials of Oedipus, e.g., the reconciliation of the protest against the real with the moral and ontological real, was from the beginning of the drama presupposed, so that when in the end Oedipus is blind, through no fault of his own origination, the outcome seemed to all – including Oedipus – finally just.
Reality is not nice. It is not tidy. Not, at any rate, in such a way as we should like it to be, or think it ought to be. But, it is just. In no other way might it cohere from one moment to the next.
In short, modernity supposes that bodies and their inherent meanings are not real, or at least are not dispositive; so that bodies may be killed without further consideration, when convenience seems to indicate.
Christianity per contra is focused like a laser on the essentially, the inescapably embodied condition of human being. So, it emphasizes our bodies. Kill our bodies, it says to our oppressors (among our governors of this world, and among the demons whom they more or less seem always to serve – and, what is far more, and far deeper, to ourselves) – and you kill us. And that killing is evil.
Not that you can in so doing kill us permanently. We know better about that, than you. But, go ahead: knock yourselves out! Literally.
Gnosticism can’t cognize any of that. We miss this obvious fact, because we are so accustomed to life in what still remains a fundamentally Christian society – a society that, despite the suasions of the media, is in large part not yet quite completely Gnostic.
Thus the common and correct horror at the devastation of WWII. If we were not still a fundamentally Christian society, we could not feel it. A truly Gnostic society would not think that way. It would think, rather, “o well, some millions died; such is life in this defective world.”
The Christian argument is that the material human body is sacred. It is an instance full of the Temple. Indeed, the Christian argument is that matter per se, howsoever manifest, is in some degree sacred. The mouse, then, and the bird, aye and even the stone, no less – albeit, differently – than the saint, or the philosopher, are sacred. Each such is after all an outwork of the Lógos.
Saint Francis was all over this.
So then likewise are the exorcists. The demons, they say, want us to believe that our bodies are as nothing. They want us to believe, i.e., that our embodied lives are as nothing. So, they urge us to let them into our lives, and into our bodies, so as to take them from us.
Such is the counsel of despair.
Fie upon all that.