 Iamblichus brought about a shift towards religion and theology in Neoplatonism which proved crucial for the later development of this movement and for its Christian appropriation. The Reply to Porphyry, where Iamblichus rejects Porphyry’s over-confident intellectualism in theological and religious matters, is certainly our major source on debates in early Neoplatonism. Scholars have traditionally described Iamblichus’ stance as irrational, contrasting it with Plotinus and Porphyry’s rational and philosophical approach (see Dodds 1951: 285–298). Recent scholarship, however, has effectively questioned this view (see Tanaseanu-Döbler 2013). In his Reply to Porphyry (I, 2 [SS-2013: 4.5–5.11]) Iamblichus distinguishes three disciplines, each with its own distinctive methods: philosophy, theology, and theurgy. Theurgy certainly goes beyond reason and philosophy, but Iamblichus’ appeal to theurgy and rituals is based on sophisticated philosophical views and arguments dealing with the nature of divine beings and the status of human souls (see below,  Section 6).  It would therefore be misleading to draw a strict opposition between theurgy and rational methods. What is distinctive about Iamblichus vis-à-vis Plotinian Platonism is the thorough integration of theological traditions into his account of reality. This emerges in two related areas. Whether or not he wrote a work by this title, Iamblichus is the first Neoplatonist to develop a “Platonic theology” (see Proclus, Platonic Theology III, 44.1–5 [Saffrey &amp; Westerink 1968–1997]). This approach will be carried further in Athenian Neoplatonism, especially by Proclus. Plotinus had already connected the hypotheses about the One in the second part of Plato’s Parmenides with his distinction of metaphysical principles (see Enn. V, 1.8). Iamblichus goes one step further in that he connects the metaphysical reading of this dialogue with the gods of the Greek pantheon. His interpretation of Plato’s Parmenides can therefore be described not only as “metaphysical” but also as “theological”. In addition to this, Iamblichus provides a harmonising account of the different theological traditions, again paving the way for the later developments in Athenian Neoplatonism (see below,  Section 3.2).  In his Reply to Porphyry Iamblichus establishes a triad of foundational traditions: the Egyptian, the Chaldaic and the Greek, represented by the philosophical wisdom of Pythagoras and Plato. The term “Chaldaic” refers to the Chaldaean Oracles (see above,  Section 2.2).  The extant evidence suggests that Plotinus and Porphyry accorded limited significance to the Oracles which, instead, become a crucial source for Iamblichus: he wrote an extensive commentary on this work and the revealed Platonizing theology of the Oracles is an integral part of his thought. The Egyptian tradition is represented by the so-called Hermetic books and, according to Iamblichus, this is the genuine source of Greek philosophy (Reply to Porphyry I, 2 [SS-2013: 4.7–9]).