yings of Leonardo quoted in this article are taken
from _Leonardo da Vinci's Notebooks_, by E. M'Curdy. (Duckworth, 1906.)]

To Leonardo causation meant the escape from caprice; it meant a secure
relation between man and all things, in which man would gain power by
knowledge, in which every increase of knowledge would reveal to him more
and more of the supreme reason. There was no chain for him in cause and
effect, no unthinking of the will of man. Rather by knowledge man would
discover his own will and know that it was the universal will. So man
must never be afraid of knowledge. "The eye is the window of the soul."
Like Whitman he tells us always to look with the eye, and so to confound
the wisdom of ages. There is in every man's vision the power of relating
himself now and directly to reality by knowledge; and in knowing other
things he knows himself. By knowledge man changes what seemed to be a
compulsion into a harmony; he gives up his own caprice for the universal
will.

That is the religion of Leonardo, in art as in science. For him the
artist also must relate himself directly to the visible world, in which
is the only inspiration; to accept any formula is to see with dead men's
eyes. That has been said again and again by artists, but not with
Leonardo's mystical and philosophical conviction. He knew that it is
vain to study Nature unless she is to you a goddess or a god; you can
learn nothing from reality unless you adore it, and in adoring it he
found his freedom. How different is this doctrine from that with which,
after centuries of scientific advance, we intimidate ourselves. We are
threatened by a creed far more enslaving than that of the Middle Ages.
If the Middle Ages turned to the past to learn what they were to think
or to do, we turn to the past to learn what we are. They may have feared
the new; but we say that there is no new, nothing but some combination
or variation of the old. Causation is to us a chain that binds us to the
past, but to Leonardo it was freedom; and so he prophesies a freedom
that we may attain to not by denying facts or making myths, but by
discovering what he hinted--that causation itself is not compulsion but
will, and our will if, by knowledge, we make it ours.

No one before him had been so much in love with reality, whatever it may
be. He was called a sceptic, but it was only that he preferred reality
itself to any tales about it; and his religion, his worship, was the
sear