Silence is the virtue of fools.
Whatever you can, count.
It is nothing won to admit men with an open door, and to receive them with a shut and reserved countenance.
Man, being the servant and interpreter of Nature, can do and understand so much and so much only as he has observed in fact or thought of the course of nature; beyond this he neither knows anything nor can do anything.
Books will speak plain when counselors blanch.
The cause and root of nearly all evils in the sciences is this-that while we falsely admire and extol the powers of the human mind we neglect to seek for its true helps.