In the Essay Locke argues abstract ideas within the framework of the descriptivist theory of reference. For him, abstract ideas are, in many cases, conceptual ideas that play the role of “descriptions” or “descriptive contents,” determining general terms’ referents. In contrast, in the introduction of the Principles, Berkeley denies Lockean abstract ideas adamantly from an imagistic point of view, and he offers his own theory of reference seemingly consisting of referring expressions and their referents alone. However, interestingly, he mentions a (...) general term’s “definition” and suggests that it determines the scope of the term’s referents. For example, he takes up the definition of a triangle as “a plain Surface comprehended by three right Lines” and suggests that just as Locke’s general idea of a triangle does, the definition determines the referents of the general term “triangle.” His definition reminds us of the fact that as Descartes grasps the content of the general idea of a triangle as “a figure enclosed by three lines,” so Locke grasps the abstract idea of a triangle as “a Figure including a Space between three Lines,” and so on. That is, since Berkeley is an imagist, he does not acknowledge Locke’s conceptual abstract ideas as “ideas,” but although he verbally denies “abstract ideas,” his theory of reference also actually has the same descriptivist framework consisting of referring expressions, their descriptive contents, and their referents. Thus, we understand the real reason why Berkeley’s criticism of Locke seems beside the point. (shrink)

According to Kant, the division of the categories “is not the result of a search after pure concepts undertaken at haphazard,” but is derived from the “complete” classification of judgments developed by traditional logic. However, the sorts of judgments that he enumerates in his table of judgments are not all ones that traditional logic has dealt with; consequently, we must say that he chose the sorts of judgments in question with a certain intention. Besides, we know that his choice of (...) judgments and categories is strongly influenced by certain views of natural science that he fully accepts. For this reason, his argumentations are sometimes seriously inconsistent. As to Kant’s argumentations of categories, many problems have already been pointed out, but in this paper, I take up the categories of quantity and quality once more, and make clear his argumentations’ hidden logic and its distortion from the point of view of the history of logic and natural science. First, I confirm that there are non-negligible problems in his explanation to the effect that his derivation of the categories of quantity and quality is based on the quantity and quality of judgments. Next, I reconsider the meaning of his treating the categories of quantity and quality as pure concepts of the understanding. Finally, I conclude that by having recourse to the categories of quantity and quality Kant tried unjustly to apriorize the distinction between the “extensive magnitude” and “intensive magnitude” that has a long formational history since Aristotle. (shrink)