The Mereological Triangle was introduced by Hans Burkhardt in 1989 following an idea of Carlos A. Dufour. Fundamental are two distinctions. These are 1) the distinction between two kinds of totalities, a whole (either essential or essential wholes) and an aggregate or heap; 2) the distinction between two kinds of whole, the essential whole and the integral whole.
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2 Burkhardt, H.; Degen, W., (1990), “Mereology in Leibniz’s Logic and Philosophy”, Topoi, 9: 3-13.
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5 Leibniz, G. W., (1679), Characteristica geometrica. Hg. v. G. I. Gerhardt, Leibnizens Mathematische Schriften, Vol. 5, Halle, 1849-1863.
6 Libardi, M., (1994), “Application and Limits of Mereology. From the Theory of Parts to the Theory of Wholes”, Axiomathes 1, April 13-54.