In this paper I explore the ways in which Alexander of Aphrodisias employs and develops so-called ‘common notions’ as reliable starting points of deductive arguments. He combines contemporary developments in the Stoic and Epicurean use of common notions with Aristotelian dialectic, and axioms. This more comprehensive concept of common notions can be extracted from Alexander’s commentary on Metaphysics A 1–2. Alexander puts Aristotle’s claim that ‘all human beings by nature desire to know’ in a larger deductive framework, and adds weight to Aristotle’s use of the common understanding of the notion of ‘wisdom’. Finally I will indicate how these upgraded common notions are meant to play an important role in the general framework of metaphysics as a science.