Commentary on Aristotle's Metaphysics

This monumental commentary represents Albert the Great's systematic engagement with Aristotelian metaphysics and its implications for understanding divine existence and nature. Written during the height of scholastic philosophy, Albert's work demonstrates the thirteenth-century attempt to reconcile Aristotelian natural philosophy with Christian theological commitments while preserving the integrity of philosophical demonstration.

Albert approaches Aristotle's Metaphysics with remarkable comprehensiveness, examining each book's arguments concerning substance, actuality, potentiality, and ultimately the Prime Mover. His commentary reveals how medieval thinkers appropriated Aristotelian categories to articulate sophisticated proofs for God's existence. Albert particularly develops Aristotle's argument from motion, clarifying how the necessity of an unmoved mover follows from the impossibility of infinite regress in essentially ordered causal series. He strengthens this demonstration by addressing potential objections that Aristotle left unexamined, showing how self-motion and circular causation fail to eliminate the need for a first principle.

The work's significance extends beyond mere exegesis. Albert transforms Aristotle's Prime Mover—conceived primarily as final cause—into a more robust notion of God as pure actuality possessing intelligence and will. This philosophical enrichment occurs through careful argumentation rather than theological assertion. Albert demonstrates how the Prime Mover's nature as pure actuality entails perfect knowledge, showing that thought thinking itself must encompass knowledge of all possible effects. His analysis bridges Aristotelian metaphysics and the God of revealed religion without conflating philosophical and theological methods.

Methodologically, Albert employs the questio format, raising objections and providing detailed responses that clarify Aristotle's often compressed arguments. This approach allows him to address contemporary debates, particularly against Islamic philosophers like Averroes who interpreted Aristotle as limiting God's knowledge to universals. Albert argues forcefully that divine simplicity and perfect actuality require God's knowledge to extend to particulars, though in a manner consistent with divine immutability.

The commentary profoundly influenced subsequent natural theology, especially through Albert's student Thomas Aquinas. By establishing reason's capacity to demonstrate God's existence and certain divine attributes independently of revelation, Albert's work legitimizes philosophical theology as a distinct discipline. His careful distinctions between what reason can establish—God's existence, unity, and certain attributes—and what requires revelation—Trinity, Incarnation—became paradigmatic for later scholasticism. The commentary thus stands as a foundational text in the Western tradition's attempt to provide rational justification for theistic belief.