Aristotle

The towering Greek philosopher, student of Plato and tutor of Alexander the Great, whose works on logic, metaphysics, ethics, and natural science became the intellectual foundation of Western thought. His concept of the 'Unmoved Mover' — a perfect, self-sufficient being that causes all motion without being moved — provided medieval Christian theologians, especially Thomas Aquinas, with a rational framework for arguing God's existence. Aristotle's student Alexander the Great spread Greek language and culture across the known world through his conquests, creating the Hellenistic civilization in which the New Testament was written in Greek (Koine) and the Septuagint translated. Without Aristotle's intellectual legacy and Alexander's cultural legacy, the rapid spread of the gospel across the Roman Empire would have looked profoundly different.