In this paper, I explore a seldom-recognized connection between the ontology of abstract objects and a current issue in the philosophy of chemistry. Specifically, I argue that realism with regard to universals implies a view of chemical elements similar to F.A. Paneth’s thesis about the dual nature of the concept of element.

The iterative conception of set commonly is regarded as supporting the axioms of Zermelo-Fraenkel set theory (ZF). This paper presents a modified version of the iterative conception of set and explores the consequences of that modified version for set theory. The modified conception maintains most of the features of the iterative conception of set, but allows for some non-wellfounded sets. It is suggested that this modified iterative conception of set supports the axioms of Quine's set theory NF.

Philosophers long have noted that some sensations (particularly those of color) seem to be ineffable, or refractory to verbal description. Some proposed neurophysiological explanations of this ineffability deny the intuitive view that sensations have inherently indescribable content. The present paper suggests a new explanation of ineffability that does not have this deflationary consequence. According to the hypothesis presented here, feedback modulation of information flow in the cortex interferes with the production of narratives about sensations, thereby causing the subject to assess (...) as inadequate his or her own verbal descriptions of sensations. (shrink)