This monograph identifiesthe essential characteristics of the objects described by current quantum theoryand considers their relationship to space-time.In the process, it explicates the senses in which quantum objects may be consistently considered to have parts of which they may be composed or into which they may be decomposed. The book also demonstrates the degree to which reduction is possible in quantum mechanics, showing it to be related to the objective indefiniteness of quantum properties and the strong non-local correlations that can occur betweenthephysical quantities of quantum...