The great natural forces lie outside us and we are not conscious of them; we call those forces gravitation, inertia, electricity, animal force, and so on, but we are conscious of the force of life in man and we call that freedom.

But just as the force of gravitation, incomprehensible in itself but felt by every man, is understood by us only to the extent to which we know the laws of inevitability to which it is subject (from the first knowledge that all bodies have weight, up to Newton’s law), so too the force of free will, incomprehensible in itself but of which everyone is conscious, is intelligible to us only in as far as we know the laws of inevitability to which it is subject (from the fact that every man dies, up to the knowledge of the most complex economic and historic laws).

All knowledge is merely a bringing of this essence of life under the laws of reason.