"We" say there are subjective idealists and objectie idealists. Plato and Hegel were objective ( "realistic") idealists - reality is an idea, "the real world is only the external, phenomenal form of "the Idea". Bishop Berkeley and Hume were subjective idealists, at least in some of their most famous discussions.
As Marx says: "My dialectic method is not only different from the Hegelian, but is its direct opposite. To Hegel, the life-process of the human brain, i.e., the process of thinking, which, under the name of "the Idea," he even transforms into an independent subject, is the demiurgos of the real world, and the real world is only the external, phenomenal form of "the Idea." With me, on the contrary, the ideal is nothing else than the material world reflected by the human mind, and translated into forms of thought. " http://www.marxists.org/archive/marx/works/1867-c1/p3.htm CB * From: ravi > > also, i notice that in phil of math, platonism (godel) and realism (putnam) seem to be (for various reasons) used somewhat interchangeably. and then there is physicalism, fregean platonism, nominalism... found this interesting bit in the bulletin of symbolic logic: http://www.math.ucla.edu/~asl/bsl/0101/0101-004.ps The Bulletin of Symbolic Logic Volume 1, Number 1, March 1995 PLATONISM AND MATHEMATICAL INTUITION IN KURT GODEL'S THOUGHT CHARLES PARSONS The best known and most widely discussed aspect of Kurt Godel's philosophy of mathematics is undoubtedly his robust realism or platonism about mathematical objects and mathematical knowledge. This has scandalized many philosophers but probably has done so less in recent years than earlier. Bertrand Russell's report in his autobiography of one or more encounters with G "odel is well known: Godel turned out to be an unadulterated Platonist, and apparently believed that an eternal "not" was laid up in heaven, where virtuous logicians might hope to meet it hereafter. On this Godel commented: Concerning my "unadulterated" Platonism, it is no more unadulterated than Russell's own in 1921 when in the Introduction to Mathematical Philosophy . . . he said, "Logic is concerned with the real world just as truly as zoology, though with its more abstract and general features." At that time evidently Russell had met the "not" even in this world, but later on under the influence of Wittgenstein he chose to overlook it.
