#  History of Philosophy Workshop: Victor Caston (University of Michigan) "Idealism and Greek Philosophy: Appearance and Reality in Aristotle & Alexander of Aphrodisias" 

 



####  calendar\_today Date and Time 

 **April 17, 2026** 

 03:00PM - 05:00PM EDT 

####  pin\_drop Location 

 **Emerson Hall 305**  



 

 



 

Abstract: Myles Burnyeat famously claimed that idealism is “one of the very few major philosophical positions which did not receive its first formulation in antiquity” and so Bishop Berkeley was wrong to find his own views in Plato and Aristotle. But this is mistaken. Aristotle attacks idealism in Metaphysics Gamma 6: those who accept Protagoras’ homomensura, that “man is the measure of all things,” he claims, make all things relative, because anything that appears appears to a subject. His arguments presuppose not just the Measure Doctrine – that anything that appears to someone is (exists, is the case) – but its converse as well, that anything that is (exists, is the case) appears to someone. Protagoras’ homomensura is often assumed to involve both directions. But the Converse Measure Doctrine is much more radical, for it implies that nothing can be (exist, be the case) unless it appears to some mind. Alexander of Aphrodisias’ commentary on Metaphysics Gamma is explicit on the point: he repeatedly states that on such a view what it is to be is to be perceived, much like Berkeley’s esse est percipi, or, as Alexander once puts it, the being of beings consists in their appearing. There is, then, a very clear formulation of idealism in antiquity, and Aristotle and Alexander both argue against it: if some things are not essentially relative, then such idealism must be rejected.



 

 



 

 

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