IN THE process of clarifying a concept already in general use, it is as unwise to neglect popular sense as it is to retain it unrefined. Beginning, then, with common-sense meanings as recorded in dictionaries, we learn that an is a standard of excellence, a goal, a purpose, or model; it is an imagined something acting in the capacity of a guide or norm. These everyday usages serve as rough delimitations of the area to which the term applies, but they lack the precision and indications of systematic relatedness which philosophic discourse demands. They leave us with the helpful but vague notion that in certain circumstances human beings entertain in imagination states of affairs thought of as superior in value and useful as guides or standards. If we follow the suggestion contained in these common usages, as I think we must if we are to retain contact with the experience within which our practical problems occur, we must say that the genus of ideal is idea. An is something held in imagination, an idea; but not all ideas are commonly called ideals. With what species of idea are we here concerned? An implication of the dictionary treatment quoted is that all ideas may be divided roughly into those which are more or less accurate reflections of experienced data and those which are in some respect novel. Ideals, as imagined states of affairs, belong to the latter group. An ideal, we may say, is an imaginal construct, i.e., an idea which is novel, in relation to actually experienced data, in degree of quality, in arrangement of elements, in extent of application, or in two or more of these respects. Usage cautions, however, that not all imaginal inventions are ideals. The evils depicted in fiction are not ideals; the invented aspects of a hypothesis about the unknown, e.g., the possible happenings of the next decade or the genes in biological theory, are not necessarily ideals. The hint is that an is only one sort of imaginal invention, namely, that which is of a valuable situation. This does not mean that an is a value but, rather, that it is a situation-in-idea which has value. But common usage reflected upon leads to a further distinction. Not even all valuable situations as constructed and held in idea are considered ideals. I might imagine a new teaching method which would seem valuable to me or a novel and valuable arrangement of articles on my desk without feeling impelled to call either ideal. An ideal, apparently, is an imagined construct of superior value; and the superiority asserted is with regard to something in experience which has fallen short in some manner and which has in its inadequacy provided the stimulus to the construction involved. An ideal, thus, is a consequence not of a simple value decision but of the more complex evaluative judgment. On the basis of clues gleaned from popular usage we may now give a refined though yet relatively simple definition of our problematic concept: An is an imaginal reconstruct of some experienced situation, or type of situation, embodying an evaluative judgment to the