Probably no invention came more easily to man than heaven.

We cannot remember too often that when we observe nature, and especially the ordering of nature, it is always ourselves alone we are observing.

A man is never more serious than when he praise himself.

Just as the performance of the vilest and most wicked deeds requires spirit and talent, so even the greatest demand a certain insensitivity which under other circumstances we would call stupidity.

What we have to discover for ourselves leaves behind in our mind a pathway that can be used on another occasion.

The sure conviction that we could if we wanted to is the reason so many good minds are idle.

To write brashly about some things, it is almost necessary not to know much about them.