"The light of natural reason is not less certain than that of revelation."

"It is a mark of a truly great mind to be able to make a great discovery with few means."

"The will, as far as it is considered formally in itself, is one of the chief perfections of man."

"The senses alone are not sufficient to give us a clear and distinct knowledge of things."

"I would not advise anyone to read my books who has not the leisure and inclination to meditate seriously with me."