Men are mortal. So are ideas. An idea needs propagation as much as a plant needs watering. Otherwise both will wither and die.
Bad ideas never die. They go to California in the hope they’ll eventually become law.
No idea is ever dead until those who believe in it say it's dead.
A man may die, nations may rise and fall, but an idea lives on.
Defeat is a fact and victory can be a fact. If the idea is good, it will survive defeat, it may even survive the victory.
Ideas percolate. Through natural selection, the best ones survive.
New ideas need audiences like flowers need bees. No matter how bright and colorful, they will die unless others work to spread them
A defeated argument that refuses to be obliterated can remain very alive.