"I always wanted to learn to distinguish the true from the false, in order to see clearly in my actions and to walk with confidence in this life."

"Our knowledge of the external world is derived from our senses, and our senses are often unreliable."

"I am a thinking substance, that is, a mind, or soul, or intellect, or reason."

"I have been nourished by books, and I have found in them a great deal of good as well as a great deal of evil."

"All that is needed to arrive at the truth is good sense, which is naturally equal in all men."