"A well-spent day brings happy sleep."

"All our knowledge has its origins in our perceptions."

"Although nature commences with reason and ends in experience it is necessary for us to do the opposite, that is to commence with experience and from this to proceed to investigate the reason."

"Anyone who conducts an argument by appealing to authority is not using his intelligence; he is just using his memory."

"Art is never finished, only abandoned."

"As a well-spent day brings happy sleep, so a life well spent brings happy death."

"As every divided kingdom falls, so every mind divided between many studies confounds and saps itself."

"Beyond a doubt truth bears the same relation to falsehood as light to darkness."

"Common Sense is that which judges the things given to it by other senses."

"Experience does not err. Only your judgments err by expecting from her what is not in her power."