“The man who cannot listen to an argument which opposes his views either has a weak position or is a weak defender of it. No opinion that cannot stand discussion or criticism is worth holding. And it has been wisely said that the man who knows only half of any question is worse off than the man who knows nothing of it. He is not only one sided, but his partisanship soon turns him into an intolerant and a fanatic. In general it is true that nothing which cannot stand up under discussion and criticism is worth defending.”