A man would create another man if one did not already exist, but a woman might live an eternity without even thinking of reproducing her own sex.

To make an epoch in the world, two conditions are manifestly essential-a good head and a great inheritance.

Error is to truth as sleep is to waking. I have observed that one turns, as if refreshed, from error back to truth.

To know where a thing is we must have found it.

What is fruitful alone is true.

Well-mannered children could be conceived if the parents were well-mannered.

We can most safely achieve truly universal tolerance when we respect that which is characteristic in the individual and in nations, clinging, though, to the conviction that the truly meritorious is unique by belonging to all of mankind.