We can never be sure that the opinion we are endeavoring to stifle is a false opinion; and if we were sure, stifling it would be an evil still. – John Stuart Mill, On Liberty, 1859
The aim of education should be to teach us rather how to think, than what to think — rather to improve our minds, so as to enable us to think for ourselves, than to load the memory with thoughts of other men. – Bill Beattie