Liber de Causis (The Book of Causes)

(a) Self-subsistent substances are simple substances [Prop. 28/XXVII]

(b) Simple substances are self-subsistent substances [Prop. 29/XXVIII]

(3) Diversity of eternity and time: [Props. 30–32/XXIX–XXXI]

(a) Relations between temporal substances [Prop. 30/XXIX]

(b) Relations between eternal substances [Prop. 31/XXX]

(c) Status of Soul [Prop. 32/XXXI]

As the above division of the text clearly shows, for the author of The Book of Causes, the universe is a cosmos—that is, a world-system structured according to the basic metaphysical laws of Neo-Platonism. The first and most fundamental of these is the principle of causality. The universe is, in fact, an ensemble of causes and effects of primary