From Self-Development and the Way to Power, by L. W. Rogers (20)

All the business activities of the world are developing the will.
Through them will and desire work together in evolving latent powers.
Desire arouses will power. A man desires wealth and the desire plunges
him into business activities and stimulates the will by which he
overcomes all the difficulties that lie in his way. Ardent desire for
an education arouses the will of the student and the awakened will
triumphs over poverty and all other barriers between him and the
coveted diploma. If a man stands at a lower point in evolution where
he has not the ambition for intellectual culture nor for fame nor for
wealth, but only the desire for shelter and food, still that primitive
desire forces him into action; and while his will power will be
evolved only in proportion to the strength of the desire that prompts
him, it must nevertheless grow. Instead of rising at a certain hour
because the will decrees it he may rise only because he knows his
livelihood depends upon it. But he is learning the same lesson--the
overcoming of the inertia of the physical body--albeit it is
compulsory instead of voluntary. But all this is unconscious
evolution. It is the long, slow, painful process. It is the only way
possible for those who are not wise enough to co-operate with nature
in her evolutionary work and thus rise above the necessity of
compulsion.