THE PHILOSOPHY OF LEIBNIZ: A CRITIQUE

Author of works such as Discourse on Metaphysics (1686), the New System of Nature and the Interaction of Substances (1695), Essays in Theodicy (1710), The Principles of Nature and Grace (1714), Monadology (1714), and New Essays Concerning Human Understanding (posthumous, 1765) the immanentist 1 Gottfried Wilhelm Leibniz (1646-1716) formulated his own rationalist and essentialist versions of the ontological argument throughout his works, 2 wherein he sought to improve upon Descartes's rationalist formulation of the ontological argument. In his Nouveaux essais sur l'entendement humain, which appeared postumously in 1765, Leibniz writes that "the Scholastics, not excepting their Doctor Angelicus, have misunderstood this argument and have taken it as a paralogism. In this respect they were altogether wrong, and Descartes, who studied the Scholastic philosophy for quite a long time at the Jesuit college of La Flèche, had great reason for re-establishing it. It is not a paralogism, but it is an imperfect demonstration, which assumes something that must still be proved in other to render it mathematically evident; that is, it is tacitly assumed that this idea of the all-great or allperfect Being is possible and implies no contradiction." 3 For the author of the Essays in Theodicy and the Monadology, once one is able to demonstrate that the idea of a supremely perfect Being is the idea of a possible Being, then "it could be said that the existence of God was demonstrated geometrically a priori." 4 A common formulation of Leibniz's ontological argument would go like this: It is possible for God to exist, since that does not involve contradiction. But if God is 1 For the immanentist Leibniz, "l'oggetto immediato della conoscenza è sempre interno all'anima, è sempre l'idea, poiché un oggetto esterno non potrebbe influire sull'anima."(S. VANNI ROVIGHI, Gnoseologia, Morcelliana, Brescia, 1963, p. 157). Thonnard writes that "Leibniz can be said to be more idealist than either Descartes or Spinoza. While the view of pre-established harmony, like a 'deus ex machina,' safeguards the objective reality of the world and of its order, our monad-soul knows only its subjective modifications and its ideas, which is sheer idealism. Furthermore, the theory of simple monads deprives the ideas of extension and of space of any objective value. Thus, despite an attempt in favor of traditional philosophy, Leibniz actually developed the idealistic germs of Cartesianism, favoring the unity of 'thought' to the detriment of extension."(F.-J. THONNARD, A Short History of Philosophy, Desclée, Tournai, 1956, p. 564). Benignus Gerrity likewise notes the immanentist idealism of Leibniz, stating that "Leibniz did not even pretend that the mind in any way gets extra-mental reality into itself; all knowledge is purely internal. The self-conscious monad which, according to Leibniz, is the human soul, represents all the other monads which make up the world, but this representation, which is knowledge, is not the result of any interaction between the mind and external things or of any presence of external things to the mind for every monad is perfectly self-contained and interacts with no other. The mind's representations correspond with-i.e., representthe external world of the other monads, because God had created all monads in 'pre-established harmony.

not only affirmed an immanentist (and therefore invalid) version of the demonstration of the existence of God a contingentia mundi, but he also formulated and presented his own rationalist version of the ontological argument. "Besides his cosmological proof of God's existence Wolff accepted the ontological argument, being persuaded that the development of this argument by Leibniz and himself had rendered it immune from the usual lines of criticism." 1 Wolff's rationalist ontological argument for the existence of God is found in the second volume of his Theologia naturalis methodo scientifica pertractata (2 vols., Frankfurt and Leipzig, 1736-1737). Concerning Wolff's rationalist version of the ontological argument, Étienne Gilson and Thomas Langan write: "What about Necessary Being itself? To conceive it as deprived of any sufficient reason, and therefore of any cause, is to make it a metaphysical impossibility. The answer to the problem had already been hinted at by Descartes, but it found in the natural theology of Wolff its complete formulation. Since God is the only being that is by itself (ens per se), and since we call 'being by itself' such a being as has in its essence the reason for its existence, God exists by his essence-Deus per essentiam suam existit. 2 No stronger formula of the primacy of essence over existence can be found than Wolff's definition of God as that being 'from whose essence existence necessarily follows.' 3 In this doctrine where being is one with possibility, God finds in his very possibility the very reason for

Critique of Leibniz's Ontological Argument. Leibniz has his own formulation of the ontological argument for the existence of God, wherein he sought to improve upon Descartes's version of the ontological argument. Leibniz writes in his New Essays Concerning Human Understanding (Nouveaux essais sur l'entendement humain), which appeared postumously in 1765: "The Scholastics, not excepting their Doctor Angelicus, have misunderstood this argument and have taken it as a paralogism. In this respect they were altogether wrong, and Descartes, who studied the Scholastic philosophy for quite a long time at the Jesuit college of La Flèche, had great reason for re-establishing it. It is not a paralogism, but it is an imperfect demonstration, which assumes something that must still be proved in other to render it mathematically evident; that is, it is tacitly assumed that this idea of the all-great or all-perfect Being is possible and implies no contradiction." 1 For Leibniz, once one demonstrates that the idea of a supremely perfect Being is the idea of a possible Being, then "it could be said that the existence of God was demonstrated geometrically a priori." 2 Leibniz's ontological argument goes like this: It is possible for God to exist, since that does not involve contradiction. But if God is possible, He must exist, since a God who is merely possible is not that which is understood by 'God.' Therefore, God really exists. He writes the following in his Monadology: "God alone (or the Necessary Being) has this prerogative that if He be possible He must necessarily exist, and, as nothing is able to prevent the possibility of that which involves no bounds, no negation, no contradiction, this alone is sufficient to establish a priori His existence." 3

una tale confusione basterebbe a interdire, come osserva san Tommaso, la fondazione della prova dell'esistenza di Dio su una idea a priori di Dio." 15 2. Descartes. Descartes's Ontological Argument. René Descartes (1596-1650) gives his rationalist formulations of the ontological argument for the existence of God in Part IV of the Discourse on Method (Discours de la méthode, 1637), 16 in the Fifth Meditation 17 of his Meditations on First Philosophy (Meditationes de prima philosophia, 1641), in his Reply to the First Set of Objections, 18 Reply to the Second Set of Objections, 19 and Reply to the Fifth Set of Objections 20 in the Objections and Replies attached to the Meditations, in his Letter to Mersenne of July 1641, 21 in Principle XIV (and Principle XV) of Part I of his Principles of Philosophy (Principia philosophiae, 1644), and in his Notes Directed Against a Certain Progamme (Notae in Programma Quoddam, 1648, also known as Comments on a Certain Broadsheet). 22 Even though he is aware of the various criticisms made against the ontological argument by past thinkers (most notably by St. Thomas Aquinas), he nevertheless asserts that his own distinctive formulations of this type of argument do demonstrate the existence of God, are in fact valid demonstrations of the existence of God. Copleston notes that "in the fifth Meditation (in the French version) Descartes speaks of the ontological argument as 'demonstrating the existence of God.' 23 …Moreover, in the Principles of Philosophy, 24 he gives the ontological argument first and clearly says that it is a demonstration of God's existence." 25 Descartes' ontological argument in his Reply to the First Set of Objections is stated by him as follows: "My argument is of the following kind-That which we clearly and distinctly understand to belong to the true and immutable nature of anything, its essence, or form, can be truly affirmed of that thing; but, after we have with sufficient accuracy investigated the nature of God, we clearly and distinctly understand that to exist belongs to His true and immutable nature; therefore we can with truth affirm of God that He exists." 26 In an earlier work, his 1637 Discours de la méthode, he presents his ontological argument in Part IV as follows: "I saw very well that if we suppose a triangle to be given, the three angles must certainly be equal to two right angles; but for all that I saw no reason to be assured that there was any such triangle in existence, while on the contrary, on reverting to the examination of the idea which I had of a Perfect Being, I found that in this case existence was implied in it in the same manner in which the equality of its three angles to two right angles is implied in the idea of a triangle; or in the idea of a sphere, that all the points on its surface are equidistant from its centre, or even more evidently still. Consequently it is at least as