The most important knowledge is that which guides the way you lead your life.

The only absolute knowledge attainable by man is that life is meaningless.

I only hope that when I am free, as they are free to go in quest, of the knowledge beyond the bounds of life, it may not seem better to me to rest.

What's done cannot be undone.

All knowledge which ends in words will die as quickly as it came to life, with the exception of the written word: which is its mechanical part.

I have been impressed with the urgency of doing. Knowing is not enough; we must apply. Being willing is not enough; we must do.