The strength of the human spirit knows no boundaries.

Anything the human mind can believe, the human mind can achieve.

el espíritu humano está hecho de tal suerte, que le es más accesible la ficción que la verdad.

It is possible for the human spirit to win after all.

The greatest achievement of humanity is the human spirit.

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

Spirit is man's new power if he is to be truly mighty in his civilization.

Intuition is a very powerful thing, more powerful than intellect, in my opinion.

Whatever the mind of man can conceive and believe, he can achieve.

Genius is a power of the soul and that powers of the soul can be developed by everyone. (p. 8)

the most awesome power every human being possesses: the power to influence earth from heaven through prayer.

I believe we are powerful, but we don’t use our minds to full capacity. Your mind is powerful enough to help you attain whatever you want.

How amazing is the spirit of man!...it is impossible to lose hope for him. In the midst of disaster he has not lost his dignity or his faith in the values he cherished. Plaything of nature's mighty forces, less than a speck of dust in this vast universe, he has hurled defiance at the elemental powers, and with his mind, cradle of revolution, sought to master them. Whatever gods there may be, there is something godlike in man, as there is something of the devil in him.
The future is dark, uncertain. But we can see part of the way leading to it and can tread it with firm steps, remembering that nothing that can happen is likely to overcome the spirit of man which has survived many perils. Remembering also that life, for all its ills, has joy and beauty, and we can always wander,if we know how to, in the enchanted woods of nature.

Whatever the mind of man can conceive and believe, it can achieve