How does the Trinity illuminate our understanding of humanity? This study takes up the question of the dogmatic foundations for a 'trinitarian' anthropology, and argues that this foundation is found in the teaching of the so-called 'Christological' Councils: Ephesus (431), Chalcedon (451), Constantinople II (553) and Constantinople III (680-1). Recent patristic scholarship has renewed our understanding of the theological motivations of the principal protagonists in the debates behind these Councils. One important result of such scholarship is a renewed focus of the soteriological motivations as key to understanding the teaching of these Councils. The author brings this result into dialogue with contemporary theology's desire to retrieve the trinitarian dimensions of theological discourse, arguing that soteriology rather than revelation should be recognized as primary. Salvation is human participation in the trinitarian life. This participation is made possible, not so much through the revelation that God is Trinity, but through the economy of salvation culminating in the Incarnation and Resurrection of Jesus. Far from relativizing the humanity of Jesus in favour of his divinity, as is often suspected, these Councils make Jesus' humanity the basis for the Christian understanding of humanity as such. The author argues that any attempt to relate the Trinity to theological anthropology must take its cues not from theological reflection on the Trinity in se, but from the trinitarian shape of the economy of salvation; not from theologia, but from oikonomia.