Reading is equivalent to thinking with someone else's head instead of with one's own.

With people of limited ability modesty is merely honesty. But with those who possess great talent it is hypocrisy.

Men are the devils of the earth, and the animals are its tormented souls.

The fourfold root of the principle of sufficent reason is "Anything perceived has a cause. All conclusions have premises. All effects have causes. All actions have motives.

The greatest intellectual capacities are only found in connection with a vehement and passionate will.

Gaiety alone, as it were, is the hard cash of happiness; everything else is just a promissory note.

There are three stages in the revelation of truth. The first is to be ridiculed, the second is to be resisted and the third is to be considered self-evident.