Date of Award


Degree Type


Degree Name

Master of Arts in Philosophy



First Advisor

John Peterson


The Third Man Argument, which made its first recorded appearance in the philosophy of ancient Greece, has most often been thought of as an attack upon Plato's Theory of Forms. Plato’s theory, of course, accommodated two types of ‘man’: the Form and the particular. The Form was that which two or more particular men were said to be like one another ‘in virtue of.’ Plato had sought to restore the notion of stability in a world of apparent flux. Forms were unchanging, perfect, and independent. Particulars were changing, imperfect, and dependent upon the Forms for their being.

The Third Man Argument (actually there are three versions--two pointing out a 'third man’ in addition to the Form and particular, and one yielding not only a third man,’ but an indefinite number) attempts to show a flaw in Plato’s Theory of Forms. What is indeed strange is the fact that Plato presents the argument himself in his dialogue the Permenides and seemingly leaves it unanswered. This has led commentators to a host of interpretations, pronouncing the argument valid or invalid, finding its role in Plato’s development either significant or insignificant.

It is the purpose of this study to analyze the various versions of the Third Man Argument, to examine commentaries on them, to judge the validity of the arguments and their significance to Plato’s philosophy. It is my finding that Plato was certainly aware of the argument he was presenting -- that he was actually using it to purge his followers of false notions of his theory arising, apparently, from taking his metaphorical language too literally. That he was aware of the difficulty of finding the right words, is seen, I think, in his dialogue Cratylus, It is my contention, however, that Plato knew the argument was valid (although not against his actual theory) and goes on in the Parmenides to set his followers straight -- presenting a dialectical exercise (far from being a ‘joke’ as some have supposed) showing the necessity of certain combinations of Forms and indirectly implying that the Third Man Argument can be answered. Further it is possible that Plato had attempted to forestall a ‘third man’ as early as the Republic (with the now-famous Third Bed Argument). And with more technical terminology of recent times (via R. E. Allen), identifying Forms as ‘exemplary causes’ and particulars as ‘relational entities,’ I think that Plato's theory can be understood in such a way to hinder the entrance of any ‘third man.’ But the role that the Third Man Argument plays in Plato's philosophy is not so much a step in his development as it is a step to forestall others from developing his theory into something it was never intended to be.



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