Online research in philosophy

In this paper the machinery and results developed in [Awodey et al, 2004] are extended to the study of constructive set theories. Specifically, we introduce two constructive set theories BCST and CST and prove that they are sound and complete with respect to models in categories with certain structure. Specifically, basic categories of classes and categories of classes are axiomatized and shown to provide models of the aforementioned set theories. Finally, models of these theories are constructed in the category of ideals.

Much recent work on Aristotle's Categories assumes that there is an ontological theory presented in that work and tries to reconstruct it on the basis of the slender evidence in the book. I claim that this is misguided. Using a distinction made by G.E.L. Owen between theory and the "phaenomena", I argue that the Categories is mainly concerned with setting out the phenomena -- the intuitions that any ontology must explain. This thesis has consequences for the interpretation of Aristotle's ontological writings. I explore some of these.

Grammatical categories of English expressions are shown to differ with regard to the freedom we have in semantically interpreting their lexical (= syntactically simplest) expressions. Section 1 reviews the categories of expression we consider. Section 2 empirically supports that certain of these categories are lexically free, a notion we formally define, in the sense that anything which is denotable by a complex expression in the category is available as a denotation for lexical expressions in the category. Other categories are shown to be not lexically free. Thus for those categories the interpretation of lexical expressions is inherently constrained compared to the interpretation of the full class of expressions in the category.

This paper provides an account of Kant's categories of freedom, explaining how they fit together and what role they are supposed to play. My interpretation places particular emphasis on the structural features that the table of the categories of freedom shares with the table of judgements and the table of categories laid out by Kant in the Critique of Pure Reason. In this way we can identify two interpretative constraints, namely (i) that the categories falling under each heading must form a synthetic unity whereby the third one derives from the combination of the other two. and (ii) that the first two categories falling under each heading must be morally undetermined and sensibly conditioned, while the third category is sensibly unconditioned and determined only by the moral law.

This paper addresses the problem of the origin and principle of Aristotle’s distinctions among the categories. It explores the possibilities of reformulating and reviving the “grammatical” theory, generally ascribed first to Trendelenburg. The paper brings two new perspectives to the grammatical theory: that of Aristotle’s own theory of syntax and that of contemporary linguistic syntax and semantics. I put forth a provisional theory of Aristotle’s categories in which (1) I propose that the Categories sets forth a theory of lexical structure, with the ten categories emerging as lexical or semantic categories, and (2) I suggest conceptual links, both in Aristotle’s writings and in actuality, between these semantic categories and certain grammatical inflections.

The concept of an ontological category is central to metaphysics. Metaphysicians argue about which category of existence an object should be assigned to, whether one category can be reduced to another one, or whether there might be different equally adequate systems of categorization. Answers to these questions presuppose a clear understanding of what precisely an ontological category is, and Jan Westerhoff now provides the first in-depth analysis. After examining a variety of attempted definitions, he proceeds to argue for a new understanding of ontological categories, according to which they are systematizations of our knowledge of the world rather than essential characteristics of the world itself. Metaphysicians will find his work highly stimulating.

Elementary axioms describe a category of categories. Theorems of category theory follow, including some on adjunctions and triples. A new result is that associativity of composition in categories follows from cartesian closedness of the category of categories. The axioms plus an axiom of infinity are consistent iff the axioms for a well-pointed topos with separation axiom and natural numbers are. The theory is not finitely axiomatizable. Each axiom is independent of the others. Further independence and definability results are proved. Relations between categories and sets, the latter defined as discrete categories, are described, and applications to foundations are discussed.

I describe an account of ontological categories which does justice to the facts that not all categories are ontological categories and that ontological categories can stand in containment relations. The account sorts objects into different categories in the same way in which grammar sorts expressions . It then identifies the ontological categories with those which play a certain role in the systematization of collections of categories. The paper concludes by noting that on my account what ontological categories there are is partially interest-relative, and that furthermore no object can belong essentially to its ontological category.

A value statement such as “she is a good teacher” is categoryspecified, i.e., the criteria of evaluation are specified as those that are applicable to a given category, in this case the category of teachers. In this study of categoryspecified value statements, certain categories are identified that cannot be used to specify value aspects. Special attention is paid to categories that are constituted by functional characteristics. The logical properties of value statements that refer to such categories are shown to differ significantly from the corresponding properties in social choice theory.