The nature of the human mind is such that unless it is stimulated by images of things acting upon it from without, all remembrance of them passes easily away.

But of all other stupendous inventions, what sublimity of mind must have been his who conceived how to communicate his most secret thoughts to any other person, though very far distant, either in time or place? And with no greater difficulty than the various arrangement of two dozen little signs upon paper? Let this be the seal of all the admirable inventions of man.

ô enfance du coeur humain qui ne vieillit jamais! voilà donc à quel degré de puérilité notre superbe raison peut descendre! Et encore est-il vrai que bien des hommes attachent leur destinée à des choses d'aussi peu de valeur que mes feuilles de saule.

Who would set a limit to the mind of man? Who would dare assert that we know all there is to be known?

Hand it to him, and he will turn away. Take it from him, and he quickly runs after it.

It stands to the everlasting credit of science that by acting on the human mind it has overcome man's insecurity before himself and before nature.