Abstract
When the theory of Forms was first developed by Plato, it was the final stage of a series of philosophical investigations which began with Socrates' search for definitions. The Form was regarded as a ‘one over many’ that is separate from particulars. It is by their participation in the perfect Form that the particulars derive their transitory existence. There is a Form, according to the Republic corresponding to every set of things that have a common name. There are Forms of moral qualities, mathematical entities, and material objects. In the Parmenides Socrates admits that he is in doubt whether there are Forms of Man, Fire, and Water, but by the time of the Timaeus Plato has no doubts about Forms of the four elements, and in the Philebus he accepted a Form of Man also. This fact is well known to Aristotle, who speaks of Man as a typical Form at E.N. 1096b1. Finally, we may add that regress arguments, such as that about the Form of Largeness at Parmenides 132 ab, were generally referred to in antiquity as Third Man arguments—arguments, that is, which used the Form of Man as a paradigm for Forms in general.