The learned man knows that he is ignorant.

One of the hardest tasks is to extract continually from one's soul an almost inexhaustible ill will.

When a person opens a book, he can never be in prison.

There is one thing stronger than all the armies in the world, and that is an idea whose time as come.

Be happy without picking flaws.

Progress is the life-style of man.

Let us admit, without bitterness, that the individual has his distinct interests and can, without felony, stipulate for those interests and defend them. The present has its pardonable amount of egotism; momentary life has its claims, and cannot be expected to sacrifice itself incessantly to the future. The generation which is in its turn passing over the earth is not forced to abridge its life for the sake of the generations, its equals after all, whose turn shall come later on.