2Gottfried Wilhelm Leibniz, Philosophical Papers and Letters, A Selection Translated and Edited by Leroy E. Loemker, D. Reidel Publishing Company, Dordrecht, Holland, 1975, P687.
3Martin Heidegger, Identittat und Differenz, Gesamtausgabe, Band 11, 2005, P34.
4Phaedo, The Dialogues of Plato, translated by Benjamin Jowett. Encyclopaedia Britain Inc. 1952 ,P224.
