Leonardo da Vinci on good and evil

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.

Simplicity is the ultimate sophistication.

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

All that is required for evil to prevail is for good men to do nothing.

Edmund Burke1729–1797

Men never do evil so completely and cheerfully as when they do it from religious conviction.

Blaise Pascal1623–1662

• Anti-Religion

The world is a dangerous place, not because of those who do evil, but because of those who look on and do nothing.

Albert Einstein1879–1955