After studying the philosophy of Alfarabi, one comes to three conclusions; first, that Alfarabi brought about the first penetration of Arabism into Hellenism and of Hellenism into Arabism.
Second, that Alfarabi exerted a great influence on medieval thinkers. This is made clear by the fact that Albertus Magnus quotes Alfarabi, and evidently he could not quote him unless he had known his writings. Hence, the knowledge of the works of Alfarabi gave Albertus Magnus and his pupil, St. Thomas, an opportunity to do some sifting in the sense that they were enabled to throw out the theories that conflicted with Christian teaching and take in at the same time those that appeared to them as logically sound and reconcilable with Christianity.
Third, that Alfarabi improved many Aristotelian theories, solved many problems till then unsolved, and enriched Scholasticism with new philosophical terms, such as quiddity, a necessary being, a contingent being, the speculative and practical intellects, etc.
We have considered the philosophy of Alfarabi under a three-fold aspect: the philosophy of being (Metaphysics), the philosophy of thinking (Psychology), and the philosophy of acting (Ethics).
In the philosophy of being, Alfarabi taught that the most universal concept is being, which cannot be defined, nor re-solved into simpler concepts. Hence, the simplicity of being of the Latin Schoolmen.
The problem of universals which occupied the minds of medieval thinkers was solved by Alfarabi in the words: "Universale
est unum de multis et in multis." Hence, the traditional definition of the universal, "Aptum praedicari de pluribus."
He also believed that the nature of reality is being in becoming, that is, potentiality and actuality, substance and accident, essence and existence, matter and form, cause and effect. Is all reality that way? Certainly not. For, there is a reality which is beyond all change, and this is God. In comparing the Theodicy of Alfarabi with that of St. Thomas, we found that the latter depends on the former for the first three arguments proving God's existence, and also for the way in which God's nature is known (Via remotionis et eminentiae. )
Furthermore, Alfarabi, three hundred years before St. Thomas, taught in clear and distinct words, that the essence and existence in created things differ as different entities, while they are identical in God. This means that the Saint who came out with the same theory three hundred years later, must certainly have borrowed it from Alfarabi.
In the philosophy of thinking, he describes the history of our speculative intellect. At first it is in potentiality to all things intelligible. It passes from potentiality to act through the action or illumination coming down from above, namely, the active intellect.
In the philosophy of acting, he shows how every human activity tends to happiness. Happiness is the cause that prompts man to live in society, thus creating the state. The model state is the universal state that puts the whole world under one political organization.
In conclusion, there is a unity of thought throughout the philosophy of Alfarabi, who spared no efforts to make the various parts of his philosophical vision converge towards one living God, on Whom the one and the many, being and becoming, are essentially dependent.