A C.S.Lewis Quote

As for matters of taste and mere preference, there is room for debate. However, regarding issues of right or wrong, good or evil, there is no debate. C.S. Lewis put it best:

An open mind, in questions that are not ultimate, is useful. But an open mind about the ultimate foundations either of Theoretical or Practical Reason is idiocy. If a man's mind is open on these things, let his mouth at least be shut. He can say nothing to the purpose.

--In The Abolition of Man.