>>24677428
>I didn't say the brain constitutes causality. I said that Schopenhauer's view is that the four principles of sufficient reason together constitute the empirical world for the understanding. This word "constitute" does not refer to material causality. Material causality is one of the four roots. The union of the four roots is the "constitution" of the empirical. Nowhere, to my knowledge, does Schopenhauer describe this as being caused by the brain.
First of all, I was only talking about mechanical causality in the first place, showing how insufficient it is compared to what Kant was trying to do, and the absurd postulate of the brain. You're saying "there are these other roots... and he never speaks of the brain as the cause of all four!", an absurd non sequitur. But what does Schopenhauer himself say? I suppose I don't NEED to quote since you've already read the book...
"It is only when the Understanding begins to act—a function, not of single, delicate nerve-extremities, but of that mysterious, complicated structure weighing from five to ten pounds, called the brain—only when it begins to apply its sole form, the causal law, that a powerful transformation takes place, by which subjective sensation becomes objective perception. For, in virtue of its own peculiar form, therefore à priori, i.e. before all experience (since there could have been none till then), the Understanding conceives the given corporeal sensation as an effect (a word which the Understanding alone comprehends), which effect, as such, necessarily implies a cause. Simultaneously it summons to its assistance Space, the form of the outer sense, lying likewise ready in the intellect (i.e. the brain), in order to remove that cause beyond the organism; for it is by this that the external world first arises, Space alone rendering it possible, so that pure intuition à priori has to supply the foundation for empirical perception." Etc. etc.
You don't seem to understand what's at stake here. I'll try to spoon-feed you. If you explain material causality by the brain, then material causality isn't really grounded in anything, because it is still contingent. Schopenhauer is completely ignoring, in fact shows no awareness of, the ur-problem of idealism. This means he has no metaphysics. So far all you've done is try to wiggle out of the argument, which you don't seem to understand, and you don't even seem to have read the relevant texts.