TY - CHAP AB - This project of derivation that I have just described may seem strange, but is not. In this as in many respects Plato set the fashion for the millennia to come. The ideal state sketched in the Republic is not only an analogy to the soul (though it is that too); it is an implication of Plato's conception of human mental capacity, a conception that is ontological as well as epistemological. It was Plato who, according to Aristotle, first separated a universal (i.e., a concept) from particulars (i.e., a concept's physical embodiments or expressions). There are a multitude of chairs, very different in size, shape, color, and design, yet there is also a concept of the “chair,” in which all the physical chairs participate. The concept has no physical body and therefore in a sense exists outside time and space – it is immaterial and eternal. But Plato believed, reasonably as it seems to me, that it is real. It is real in the same way that a line or circle in Euclidean geometry is real even though it is not identical to any physical line or circle and cannot be – the Euclidean line has only one dimension, and the Euclidean circle only two, and there are no one-or two-dimensional objects in the physical world (although electrons are dimensionless), as far as we know. VL - 9 SN - 978-1-84950-465-2, 978-0-76231-378-5/1529-2134 DO - 10.1016/S1529-2134(06)09010-7 UR - https://doi.org/10.1016/S1529-2134(06)09010-7 AU - Posner Richard A. ED - Elisabeth Krecké ED - Carine Krecké ED - Roger G. Koppl PY - 2006 Y1 - 2006/01/01 TI - Cognitive Theory as the Ground of Political Theory in Plato, Popper, Dewey, and Hayek T2 - Cognition and Economics T3 - Advances in Austrian Economics PB - Emerald Group Publishing Limited SP - 253 EP - 273 Y2 - 2024/05/06 ER -