"The present state of philosophy is deplorable, and needs to be reformed."

"It is necessary to know the causes of things, and not only their effects, if we wish to have perfect knowledge."

"The study of perspective is a most noble science, and of great utility for all other sciences."

"The true wisdom is not to be found in the books of the Latins, but in the books of the Greeks and Arabs."

"The study of languages is therefore necessary for all sciences, and especially for theology."