Abstract

An ingenious study in the interplay between mereology and set theory, this book is launched innocuously enough with the thesis that a class just is the mereological sum or "fusion" of its sub-classes. The sub-classes of a class are parts of a class in the literal sense of the word "part," as trigonometry is literally a part of mathematics. We are thus urged to resist the suggestion that the word "part" applies first and foremost to the spatial parts of a material object. The atomic parts of a class being seen to be its singleton or "unit" sub-classes, a class is now to be understood on the most basic level as a fusion of singletons but for the distressing fact that how a class might have only one member was never explained to us when we first learned that a class was supposed to be "a many combined into one."