Soul and body.

Spinoza's refuge from Descartes' dualism.

It has, however, been already mentioned that this ascending movement
of abstraction does not at once and directly bring Spinoza to the
absolute unity of substance. The principle that "determination is
negation," and that therefore the absolute reality is to be found only
in the indeterminate, would lead us to expect this conclusion; but the
Cartesian dualism prevents Spinoza from reaching it. Mind and matter
are so absolutely opposed, that even when we take away all limit and
determination from both, they still retain their distinctness. Raised
to infinity, they still refuse to be identified. We are forced,
indeed, to take from them their substantial or substantive existence,
for there can be no other substance but God, who includes all reality
in himself. But though reduced to attributes of a common substance,
the difference of thought and extension is insoluble. The independence
of individual finite things disappears whenever we substitute thought
for imagination, but even to pure intelligence, extension remains
extension, and thought remains thought. Spinoza seems therefore
reduced to a dilemma; he cannot surrender either the unity or the
duality of things, yet he cannot relate them to each other. The only
course left open to him is to conceive each attribute in its turn as
the whole substance, and to regard their difference as the difference
of expression. As the patriarch was called by the two names of Jacob
and Israel, under different aspects, each of which included the whole
reality of the man, so our minds apprehend the absolute substance in
two ways, each of which expresses its whole nature.[41] In this way
the extremes of absolute identity and absolute difference seem to be
reconciled. There is a complete parallelism of thought and extension,
"ordo et connexio idearum idem est ac ordo et connexio rerum,"[42] yet
there is also a complete independence and absence of relation between
them, for each is the whole. A thing in one expression cannot be
related to itself in another expression. Hence in so far as we look at
the substance under the attribute of thought, we must take no account
of extension, and in so far as we look at it under the attribute of
extension, we must equally refuse to take any account of thought. This
parallelism may be best illustrated by Spinoza's account of