For more than sixty years, Metropolitan John (Zizioulas) of Pergamon carried on a single, patient conversation with the natural sciences, always returning to one deceptively simple question: what does it mean to be a human person? What Is Man? gathers eleven of his essays and lectures, composed between 1999 and 2019 and now brought together for the first time by Bishop Maxim Vasiljević, into a single sustained argument about the human being in an age of biology, genetics, and artificial intelligence.

Beginning with a meditation on wisdom and information, Metropolitan John moves through patristic anthropology, the theology of creation, and the human being as “priest” rather than mere steward of the natural world, before turning to some of the most urgent questions of our time: the ontological claims made by modern psychiatry, the meaning of death and euthanasia, the ethics of genetic intervention, and the promise and peril of artificial intelligence. Throughout, he refuses every reductive account of the human being, biological or spiritual, developing instead a rich, patristic theology of the person as constituted by freedom, otherness, and communion.

Learned without being remote, and urgent without ever abandoning theological seriousness, What Is Man? stands as one of the clearest introductions to Metropolitan John’s thought on the human person, and a fitting summation of a lifetime spent holding science and theology to a single standard of truth.