The improver of natural knowledge absolutely refuses to acknowledge authority, as such. For him, scepticism is the highest of duties; blind faith the one unpardonable sin.

“The deepest sin of the human mind is to believe things without evidence”

“Zeal without knowledge is fire without light”

Thomas Henry Huxley

P.S. Agnosticism simply means that a man shall not say he knows or believes that for which he has no grounds for professing to believe.