The Gospel of John is the fourth of the canonical gospels, written in Greek and generally dated to the end of the first century. It is included here for one reason: its opening is the point at which Greek philosophical vocabulary enters Christian theology, and a great deal of later philosophy depends on that moment.

The Logos prologue

The text opens by stating that in the beginning was the logos, that the logos was with God and was God, and that all things were made through it. The Greek word already carried a long philosophical history. Heraclitus had used it around 500 BC for the rational principle ordering the cosmos; the Stoics used it for the reason pervading nature; and Philo of Alexandria, writing in the decades before this gospel, used it for the intermediary between a transcendent God and the material world.

Placing that term at the opening identifies the subject of the narrative with the rational principle of Greek cosmology. Whatever the author intended, the effect was to make Christian theology a subject that Greek philosophy could be brought to bear on — and it was, immediately and for centuries. See the concept of logos for the term's fuller history.

Its philosophical afterlife

The prologue supplied the material for the christological controversies of the fourth century, for Augustine's Neoplatonic reading, and for the doctrine of the Trinity as it was formulated at Nicaea and after. The question of how the logos relates to the God it is "with" and also "is" drove several hundred years of argument and produced much of the technical vocabulary of Western metaphysics — substance, person, nature, procession.

Character of the text

The book differs markedly from the other three gospels in structure, chronology and idiom, with long discourses in place of short sayings. Scholarship treats it as a distinct tradition, and the relation between the four remains an open question in the field.