How did Greek philosophy reach medieval Europe?

Aristotle built the tools humanity still uses: logic, the categories, the method of observation. His teacher Plato spoke of ideal forms outside the world — Aristotle said: the form lives inside the thing, not outside it. It sounds like an academic quarrel. In fact it is the foundation of all Western science and theology.

Avicenna was born in 980 in Persia, in an age when Baghdad was the intellectual capital of the world. He did not merely translate Aristotle — he developed him. The distinction between essence and existence, the proof of God's existence through necessary being, the theory of the soul — all of this Avicenna added to Aristotle. And it was in exactly this form that Greek thought returned to Europe.

Maimonides was born in Córdoba in 1135. A Jew, a physician, a philosopher. His "Guide for the Perplexed" was solving the same problem as Avicenna — but for Jewish theology: how to reconcile Aristotle with the Torah. His answer: they do not contradict each other, they are speaking of one and the same thing. Thomas Aquinas read Maimonides and leaned on him directly. Without Maimonides, scholasticism would have been a different thing.

Thomas Aquinas did the impossible: he took Aristotle (whom the Church had at first banned), Avicenna, Maimonides — and showed that none of it contradicts Christianity but rather grounds it. His "Summa Theologiae" is the most magnificent synthesis of faith and reason in history. The European universities, scholasticism, the very idea that reason and faith are compatible — all of it is Thomas.

Luther was trained on scholasticism — and rose up against it. His argument: no system, no reason, no intermediary between man and God. Scripture alone, personal faith alone. It sounds like a theological quarrel — but the consequences are political, scientific, artistic. The Reformation redrew Europe. Descartes, Locke, Kant are impossible without what Luther did.