The mutual confidence on which all else depends can be maintained only by an open mind and a brave reliance upon free discussion.
The spirit of liberty is the spirit which is not too sure that it is right; the spirit of liberty is the spirit which seeks to understands the minds of other men and women.
You cannot raise the standard against oppression, or leap into the breach to relieve injustice, and still keep an open mind to every disconcerting fact, or an open ear to the cold voice of doubt.