We must needs believe with faith, whatever counsels reason may give us, that in the depths of our own bodies, in animals, in plants, in rocks, in everything that lives, in all the Universe, there is a spirit that strives to know itself, to acquire consciousness of itself, to be itself — for to be oneself is to know oneself — to be pure spirit; and since it can only achieve this by means of the body, by means of matter, it creates and makes use of matter at the same time that it remains a prisoner of it.

The Tragic Sense of Life (1913) - IX : Faith, Hope, and Charity