The Ego And His Own - pg. 21

His life is occupation with the spiritual, is - thinking;
the rest does not bother him; let him busy himself with the
spiritual in any way that he can and chooses - in devotion is
always thinking;
and therefore, Descartes, to whom this had at last become
quite clear, could lay down the proposition: "I think, that
is - I am." This means, my thinking is my being or my
life; only when I live spiritually do I live; only as spirit am
I really, or - I am spirit through and through and nothing
but spirit. Unlucky Peter Schlemihl, who has lost his shadow,
is the portrait of this man become a spirit; for the spirit's
body is shadowless. - Over against this, how different among
the ancients! Stoutly and manfully as they might bear themselves
against the might of things, they must yet acknowledge the
might itself, and got no farther than to protect their life
against it as well as possible. Only at a late hour did they
recognize that their "true life" was not that which they led in
the fight against the things of the world, but the "spiritual
life", "turned away" from these things; and,when they saw
this, they became Christians, the moderns, and innovators
upon the ancients. But the life turned away from things, the
spiritual life, no longer draws any nourishment from nature, but
"lives only on thoughts," and therefore, is no longer "life" but -
thinking.