What chance gathers, she easily scatters. A great person attracts great people and knows how to hold them together.

Common sense is the genius of humanity.

And I have again observed, my dear friend, in this trifling affair, that misunderstandings and neglect occasion more mischief in the world than even malice and wickedness. At all events, the two latter are of less frequent occurrence.

Without my attempts in natural science, I should never have learned to know mankind such as it is. In nothing else can we so closely approach pure contemplation and thought, so closely observe the errors of the senses and of the understanding, the weak and strong points of character.

Stupidity is without anxiety.

Rest not. Life is sweeping by; go and dare before you die. Something mighty and sublime, leave behind to conquer time.

Light has called forth one organ to become its like, and thus the eye is formed by the light and for the light so that the inner light may emerge to meet the outer light.