<P> The theory of Forms or theory of Ideas is Plato's argument that non-physical (but substantial) forms (or ideas) represent the most accurate reality . When used in this sense, the word form or idea is often capitalized . Plato speaks of these entities only through the characters (primarily Socrates) of his dialogues who sometimes suggest that these Forms are the only objects of study that can provide knowledge; thus even apart from the very controversial status of the theory, Plato's own views are much in doubt . However, the theory is considered a classical solution to the problem of universals . </P> <P> The early Greek concept of form precedes attested philosophical usage and is represented by a number of words mainly having to do with vision, sight, and appearance . The words, εἶδος (eidos) and ἰδέα (idea) come from the Indo - European root * weid -, "see". Eidos (though not idea) is already attested in texts of the Homeric era, the earliest Greek literature . This transliteration and the translation tradition of German and Latin lead to the expression "theory of Ideas ." The word is however not the English "idea," which is a mental concept only . </P>

Who claimed that reality is the eternal realm of the forms