It is easier for a man to burn down his own house than to get rid of his prejudices.

Experimental science is the queen of knowledge.

It is not necessarily impossible for human beings to fly, but it so happens that God did not give them the knowledge of how to do it. It follows, therefore, that anyone who claims that he can fly must have sought the aid of the devil. To attempt to fly is therefore sinful.

There are in fact four very significant stumbling blocks in the way of grasping the truth, which hinder every man however learned, and scarcely allow anyone to win a clear title to wisdom, namely, the example of weak and unworthy authority, longstanding custom, the feeling of the ignorant crowd, and the hiding of our own ignorance while making a display of our apparent knowledge.

A little learning is a dangerous thing but none at all is fatal.

Argument is conclusive, but it does not remove doubt.

To ask the proper question is half of knowing.