Charles Darwin Quote
But then with me the horrid doubt always arises whether the convictions of man's mind, which has been developed from the mind of the lower animals, are of any value or at all trustworthy. Would any one trust in the convictions of a monkey's mind, if there are any convictions in such a mind?
Charles Darwin's Works: The life and letters of Charles Darwin... ed. by his son, Francis Darwin. 2v (ed. 1896)