In 1748, Johann Joachim Spalding (1714-1804) publishes the first edition of Die Bestimmung des Menschen, an immediately acclaimed work devoted to discuss the final purpose of human existence. In fact, the seventh edition (1763) is said to promote a fruitful debate between Moses Mendelssohn (1729-1786) and Thomas Abbt (1738-1766): in the writing published by Mendelssohn as a result of the discussion (Orakel, die Bestimmung des Menschen bettreffend, 1764), the Jewish philosopher considers that the ideas expressed by Spalding are quite close to the ideas defended by G. W. Leibniz (1646-1716). This article aims to show that the similarity suggested by Mendelssohn is justified, as Spalding and Leibniz share two central thesis concerning the nature of the human soul: both believe that (i) it is immortal and (ii) it is the basis of the individual moral identity and, furthermore, the subject of rewards and punishments given in the context of the afterlife. In order to illustrate their coincidence, the article will be divided in two parts. First of all, we will pay attention to the main elements of Die Bestimmung des Menschen; afterwards, we will analyze the Leibnizian reflections on moral and spiritual identity contained within Nouveaux essais sur I 'entendement humain (1704); finally, we will complete them by making reference to a crucial passage taken from Monadologie (1710).(1)
