The world is divided into men who have wit and no religion and men who have religion and no wit. – Avicenna
The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes. – Avicenna
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. – Avicenna