In the commentary on the prologue of the Gospel of John, which Thomas Aquinas (1224/5-1274) wrote towards the end of his life, the various elements of his person and his work crystallize like in a magnifying glass: his calling as a Dominican monk, which was entirely focused on the proclamation of the Word of God; his closeness to the thought of Aristotle, whose philosophy and logic he was able to make fruitful for Christian thought; his self-understanding as a Magister of theology, for whom the Holy Scripture and its interpretation were the source and origin of all further systematics; indeed, his theology as a whole, which becomes accessible from here in its various themes. It is not without reason that his commentary has been described as "the theological work par excellence" of Thomas Aquinas and as "the greatest formulation of the doctrine of the Logos found in the Western tradition.".