Never stop because you are afraid - you are never so likely to be wrong.

The history of the human race is a continual struggle from darkness into light. It is, therefore, to no purpose to discuss the use of knowledge; man wants to know, and when he ceases to do so, is no longer a man.

The first great thing is to find yourself and for that you need solitude and contemplation - at least sometimes. I can tell you deliverance will not come from the rushing noisy centers of civilization. It will come from the lonely places.

Happiness is the struggle towards a summit and, when it is attained, it is happiness to glimpse new summits on the other side.

Never keep a line of retreat: it is a wretched invention.

Is it not in the struggle to obtain knowledge that happiness exists? I am very ignorant, consequently the conditions of happiness are mine.

Man wants to know, and when he ceases to do so, he is no longer a man.