There is nothing so disobedient as an undisciplined mind, and there is nothing so obedient as a disciplined mind.

More than those who hate you, more than all your enemies, an undisciplined mind does greater harm.

The mind is everything. What you think you become.

Be devoted to conscientiousness. Guard your own mind.

Happiness depends more upon the internal frame of a person's own mind than on the externals in the world.

There is no limit to the power of the human mind. The more concentrated it is, the more power is brought to bearon one point.