"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."

"I should know better than to believe that everything I perceive through my senses is true."

"Give me matter and motion, and I will construct the universe."

"The will is by its nature so free that it can never be constrained."

"It is not enough to apply our mind to things, but we must also apply it to ourselves."