Compendium of All Natural Science

der, such as Saturn, Jupiter, Mars, the Sun, Venus, Mercury, and the Moon: some are not so arranged, such as father, Son, Grandson, and Great-grandson. Likewise, some causes are of such a kind that they are the effectors of contraries. The same pilot, when he is present, saves the ship; when he is absent, he destroys it.

12. On the end.

The end, indeed, is that toward which a thing tends. Of ends, some are preferred, others are consequent. The preferred are of that kind such as health, which is obtained by medicines and walking. The consequent, indeed, are of that kind such as medication and walking: for first we seek health, and then those things which contribute to health.

13. How many causes each thing can have.

Moreover, it is necessary that everything which consists of matter and form have four causes. Substantial forms, however, are endowed with an end and an efficient cause only. The same has also been attained by forms adjacent to substances.

14. On causes not called such per se.

Hitherto we have discussed those which are considered causes and principles per se. Now we shall briefly touch upon those which have been accustomed to be called causes indeed, but not per se.

15. On chance and fortune.

Therefore, since chance and fortune are found in those things