David Lewis's Parts of Classes is a great book, in all respects. But one of its most interesting thesis, in my mind, is not its core thesis that standard set theory — ZFC — reduces to classical mereology + plural quantification + a primitive singleton-relation, but rather its sub-thesis of how to understand classical mereology, what Lewis calls the thesis of Composition as Identity: (CAI

Parts of Classes [Book Review] José A. Benardete Review of Metaphysics 45 (3):620-622 (1992)

Parts of Classes Oxford: Blackwell, 1991* Einar Duenger Bøhn † [email protected] David Lewis's Parts of Classes is a great book, in all respects. But one of its most interesting thesis, in my mind, is not its core thesis that standard set theory — ZFC — reduces to classical mereology + plural quantification + a

Lewis argues that it does, and that the smallest parts of any class are its one-membered "singleton" subclasses. That results in a reconception of set theory.

Particles are a concern in Space hardware. 883B Qualification can be conducted by foreign or domestic contract house, to published or changed electricals, vendor's life test burn in boards. S = on every lot, Class B & 883B = may be completed by outside contractor, and may be completed on a "similar device".

Lewis argues that it does, and that the smallest parts of any class are its one-membered "singleton" subclasses. That results in a reconception of set theory.

3/11 · The parts of speech are commonly divided into open classes (nouns, verbs, adjectives, and adverbs) and closed classes (pronouns, prepositions, conjunctions,

Modern grammars normally recognise four major word classes (verb, noun, adjective, adverb) and five other word classes (determiners, preposition, pronoun, conjunction, interjection), making nine word classes (or parts of speech) in total. But note that some grammarians use different systems and may recognise eight or ten different word classes.

Lewis argues that it does, and that the smallest parts of any class are its one-membered "singleton" subclasses. That results in a reconception of set theory.

The parts of speech are commonly divided into open classes (nouns, verbs, adjectives, and adverbs) and closed classes (pronouns, prepositions, conjunctions, articles/determiners, and interjections). The idea is that open classes can be altered and added to as language develops and closed classes are pretty much set in stone.

Parts of Classes Let us set aside the hypothesis that classes are simple proxies for their members. If a class is composed of proper parts, then it is a sum of proper parts, that is, parts that are different from the sum. 8 Talk of 'sum' is highly suggestive, but there is more than one formal explication of sum in terms of part.