Leonardo da Vinci on intelligence

Iron rusts from disuse; stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind.

Anyone who invokes authors in discussion is not using his intelligence but his memory.

Once you have flown, you will walk the earth with your eyes turned skywards, for there you have been, and there you long to return.

We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality.

Albert Einstein1879–1955Out of My Later Years (1950), Ch. 51 “The Goal of Human Existence” (1943)

• God
• Thinking

Happiness in intelligent people is the rarest thing I know.

Ernest Hemingway1899–1961Marita in Ch. 11

• Happiness

An intellectual is a man who takes more words than necessary to tell more than he knows.

Dwight D. Eisenhower1890–1969

• Clever Jabs