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Definiton distributive class/Lesniewski: classes whose elements are precisely determined (and which cannot be arbitrary agglomerations) E.g. elements of the set of teaspoons only teaspoons, no handles (Russell pro) - LesniewskiVs: those classes do not exist(pro nominalism) - Definition collective class/mereology/Lesniewski: any (arbitrary) summaries E.g. not only teaspoons, but also a collection of handles of teaspoons, as part of the set of teaspoons -" solution to Russell's paradox: mereological (collective) classes (clusters, sets) always contain themselves as an element.
Parts Oxford New York 1987