“Now it is established in the sciences that no knowledge is acquired save through the study of its causes and beginnings, if it has had causes and beginnings; nor completed except by knowledge of its accidents and accompanying essentials.”

“Now it is established in the sciences that no knowledge is acquired save through the study of its causes and beginnings, if it has had causes and beginnings; nor completed except by knowledge of its accidents and accompanying essentials.”

“Therefore in medicine we ought to know the causes of sickness and health.”

“Now it is established in the sciences that no knowledge is acquired save through the study of its causes and beginnings, if it has had causes and beginnings; nor completed except by knowledge of its accidents and accompanying essentials.”

“The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes.”

“The world is divided into men who have wit and no religion and men who have religion and no wit.”

“The fact is, the great intellectuals of the western religious tradition from Augustine to Aquinas and Peter Abelard became philosophically dominant. The intellectual tradition was preserved. The great intellectuals of the Islamic tradition like Averroes and Avicenna became heretics whose influence disappeared under the weight of rote preaching and practice. Islam as a result has a moral code, a legalistic system of right and wrong, but no evolved ethical tradition.”

“It is only rather recently that science has begun to make peace with its magical roots. Until a few decades ago, it was common for histories of science either to commence decorously with Copernicus's heliocentric theory or to laud the rationalism of Aristotelian antiquity and then to leap across the Middle Ages as an age of ignorance and superstition. One could, with care and diligence, find occasional things to praise in the works of Avicenna, William of Ockham, Albertus Magnus, and Roger Bacon, but these sparse gems had to be thoroughly dusted down and scraped clean of unsightly accretions before being inserted into the corners of a frame fashioned in a much later period.”