 That whose existence is necessary must necessarily be one essence. |
| As to the mental essence, we find it in infants devoid of every mental form. |
| The knowledge of anything, since all things have causes, is not acquired or complete unless it is known by its causes. |
| 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. |
| The world is divided into men who have wit and no religion and men who have religion and no wit. |
