Abstract
This chapter is devoted to an exposition of the main concepts and principles of standard mereology, the system originally developed by Stanislaw Leśniewski and introduced into the English-speaking world in the guise of Henry Leonard and Nelson Goodman's ‘Calculus of Individuals’. The main source for this chapter is Peter Simons', _Parts: A Study in Ontology_, in particular his instructive gradual development of standard mereology, which shows how stronger and stronger principles may be added gradually to a minimal core, until we arrive at the full-strength theory of standard mereology. Despite standard mereology's merits as a formal theory, however, it remains to be seen whether it is of any use to the metaphysician in characterizing ordinary mereological concepts, as they apply to our scientifically informed, common-sense ontology.