Why is it that foolishness repeats itself with such monotonous precision?

For the odd thing about wisdom is the more you use it the more it grows; and the more you share, the more you gain. You'd be amazed how few understand that.

...The more stupid one is the more he thinks he knows.

Optimism and stupidity are nearly synonymous.

...people always grow more foolish, unless they take care to grow wiser and wiser...

Wisdom tends to grow in proportion to one's awareness of one's ignorance.

Our greatest stupidities may be very wise.

There's nothing so absurd that if you repeat it often enough, people will believe it.

When one is wise, it's wisest to seem foolish.

For other people, I can't speak - but, personally, I haven't gotten wise on anything. Certainly, I've been through this and that; and when it happens again, I say to myself, Here it is again. But that doesn't seem to help me. In my opinion, I, personally, have gotten steadily sillier and sillier - and that's a fact.

Wisdom is one of the few things that looks bigger the further away it is.

The philosophies of one age have become the absurdities of the next, and the foolishness of yesterday has become the wisdom of tomorrow.

The subtlest wisdom can produce the subtlest folly

stupidity can be as bad as malice