[162:12] Burnet: Op. cit., p. 284.
[167:13] Plato: Theætetus, 161. Translation by Jowett. References to Plato are to the marginal paging.
[168:14] Burnet: Early Greek Philosophy, pp. 184, 187.
[171:15] Plato: Theætetus, 150 B. Translation by Jowett.
[173:16] Much ambiguity attaches to the terms "realism" and "idealism" in current usage. The first had at one time in the history of philosophy a much narrower meaning than that which it now possesses. It was used to apply to those who, after Plato, believed in the independent reality of ideas, universals, or general natures. Realists in this sense were opposed to nominalists and conceptualists. Nominalism maintained the exclusive reality of individual substances, and reduced ideas to particular signs having, like the name, a purely symbolical or descriptive value. Conceptualism sought to unite realism and nominalism through the conception of mind, or an individual substance whose meanings may possess universal validity. Though this dispute was of fundamental importance throughout the mediæval period, the issues involved have now been restated. Realism in the old sense will, if held, come within the scope of the broader epistemological realism defined above. Nominalism is covered by empirical tendencies, and conceptualism by modern idealism.
The term idealism is sometimes applied to Plato on account of his designation of ideas as the ultimate realities. This would be a natural use of the term, but in our own day it has become inseparably associated with the doctrine which attributes to being a dependence upon the activity of mind. It is of the utmost importance to keep these two meanings clear. In the preferred sense Plato is a realist, and so opposed to idealism.
The term idealism is further confused on account of its employment in literature and common speech to denote the control of ideals. Although this is a kindred meaning, the student of philosophy will gain little or no help from it, and will avoid confusion if he distinguishes the term in its technical use and permits it in that capacity to acquire an independent meaning.
[176:18] Berkeley: Principles of Human Knowledge, Part I, Fraser's edition, p. 259.
[176:19] To be distinguished from the religious sect which bears the same name.