Definitions
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 n. The discipline which deals with parts and their respective wholes.
Etymologies
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Examples

In philosophy, the study of the relationship between parts and wholes is known as mereology, and chemical interactions present fascinating ways of testing some such theories.

Third, and most importantly, note that extensionality is a theorem in standard systems of mereology, the logic of parts and wholes (for more, see the entry on mereology).

There are various problems with this response (see Wasserman 2002), but the most obvious worry is that this reply is inconsistent with another standard axiom of mereology, known as strong supplementation:

While vision's objects possess a spatial mereology and are individuated and tracked in terms of spatial features, audition's objects have a temporal mereology and are individuated and tracked in terms of both pitch and temporal characteristics.

In general, mereology is a theory of sets in the collective (mereological) sense, contrary to ordinary set theory, which describes sets in the distributive sense.

In fact, he invented mereology when he tried to solved the Russell paradox.

As Unger originally states it, the puzzle relies on a contentious principle of mereology.

This is, for example, van Inwagen's (1990) view of the matter, which results in a fuzzification of parthood that parallels in many ways to the fuzzification of membership in Zadeh's (1965) set theory, and it is this sort of intuition that also led to the development of such formal theories as Polkowsky and Skowron's (1994) “rough mereology” or Smith's (2005) theory of

Perhaps there is no room for indeterminacy in the idealized mereology of space and time as such; but when it comes to the mereology of ordinary spatiotemporal particulars (for instance) the picture looks different.

Ditto for ˜PE™, which was in fact the primitive relation in Whitehead's (1919) semiformal treatment of the mereology of events (and which is just the converse of ˜PP™).
neoteny commented on the word mereology
Mereology (from the Greek μερος, ‘part’) is the theory of parthood relations: of the relations of part to whole and the relations of part to part within a whole.
from the Stanford Encyclopedia of Philosophy article linked below.
December 14, 2009
yarb commented on the word mereology
I was hoping it would be the study of meres.
October 23, 2007
vanishedone commented on the word mereology
The Stanford Encyclopaedia of Philosophy has articles on mereology and mediaeval mereology.
October 23, 2007