 Perhaps the most conspicuous trait of Iamblichean metaphysics is its highly vertical conception of causality. For Iamblichus, an effect does not enjoy any ontological independence with respect to its cause: anything it adds amounts to failure and nothingness. This idea predates Iamblichus, but he was the first Pagan philosopher to apply it with absolute consistency. Most of his system follows from this one axiom, particularly his doctrine of the soul (see  Section 6).  The principles’ supervision always lurks in the background: see, e.g., the idea that the intelligible gods “contain” the visible gods (i.e., planets; Reply to Porphyry I, 19 [SS-2013: 45.14–20]). The idea of the vacuity of effects leads to the notion that their sole purpose is to render themselves apt to receive the influx of their causes: Iamblichus calls this epitēdeiotēs or “receptivity”. This process of adaptation accounts for most of the diversity in the phenomenal world. Another important law states that “everything is in everything according to its property”: Damascius ascribes it to both Iamblichus and Porphyry (In Philebum § 130 = Iamblichus In Philebum [D-1973: Fr. 5]). The last words are the most important: superior beings keep their prerogatives in spite of the existence of a universal homology, which means for example that causes are present to their effects as causes, i.e., are not encompassed by them or relegated to their status. In this way, Iamblichus manages to preserve at the same time the benefits of divine immanence (the world is not abandoned by the gods) and the requirement of divine transcendence, which he feels the need to constantly affirm, lest he be accused of debasing divinity.