In the first chapter of his Elementatio theologica, Proclus treated the One as the origin of all modes of multiplicity. Petrizi follows this in his commentary to this proposition, presenting the arguments for Proclus’s approach in his own way. Petrizi adheres primarily to the basic axiom that the chain of beings requires an origin. Otherwise the universe would have its origin in an Other, which for its part would have to be the One inasmuch as the first principle (= the One) should comprise all entities of the cosmos without exception. The One as the cause and origin of being as such is deemed to be the better, and takes on no qualities from what it causes. This One alone confers selfness to all other entities because, as the generator and principle of everything that follows it, it is in need of nothing.