ARGUMENTUM ANSELMI (ratio Anselmi called the ontological proof for God’s existence)—one of the attempts by Anselm of Aosta (also called Anselm of Canterbury) to show that God exists.
This argument is found in the Proslogion. In the introduction to the work we read: “I began to consider if perhaps I could not find one argument which would need no other apart from itself to show that it is right, and which alone would suffice to affirm that God truly is and that he is the highest good without need of any other, whom all other things need in order to be and to be in a good way, and also [to show] everything we believe concerning the divine substance.” The argument is expressed in the definition of God provided in the second chapter of the Proslogion: “aliquid quo nihil maius cogitari possit” (“something above which nothing greater can be thought”). According to Anselm an analysis of this definition is sufficient to show that an object matching this definition, namely God, must exist. Anselm argues as follows: “Is there therefore no such a nature, since the fool has said in his heart: there is no God? Yet with all certainty this same fool when he hears just what I am saying (something above which nothing greater can be thought) understands what he hears and it is in his intellect, even if he might not understand that it exists.” Now God (something greater than which nothing can be thought) is not in the intellect. In the intellect is a certain understanding or concept of God as something greater than which nothing can be thought. If therefore Anselm argues: “there is at least in the intellect something above which nothing greater can be thought […] but certainly that above which nothing greater can be thought cannot be only in the intellect”, he probably wants to say that the conceptual content—“something above which nothing greater can be thought”—cannot be merely a conceptual content that exists in the intellect (in the knowing subject), but it must also be a content that exists apart from the subject. Anselm argues as follows: “For if it is only in the intellect, it can be thought that it is also in reality, and this is something greater”. Evidently, it is greater for a certain content to exist in reality apart from the mind than for this content to exist only in the intellect. But the content by itself: “something above which nothing greater can be thought” is not a richer content because it exists in reality than the same content that exists only in the subject (in the intellect). Therefore Anselm is wrong when he continues his argumentation as follows: “If, then, that above which nothing greater can be thought is only in the intellect, then the same thing above which nothing greater can be thought is at the same time that above which something greater can be thought. Therefore something above which nothing greater can be thought exists without doubt in the intellect and in reality. If one holds that content—“something above which nothing greater can be thought”—exists only in the intellect, this does not lead to the conclusion that the content—“something above which nothing greater can be thought”—is identical to the content—“something above which something greater can be thought”. Therefore we may justly ask whether the content—“something above which nothing greater can be thought”—of which we think as existing in reality and apart from our thought really exists. Does the content—“something above which nothing greater can be thought” really exist? Thus the ratio Anselmi is not a demonstration of the truth of the proposition that God has a real extra-subjective existence.
Anselms’s argument has been addressed repeatedly in the history of philosophical and theological thought. Various reformulations have been proposed and some use tools of formal logic. R. Descartes, W. G. Leibniz, and in our times N. Malcolm, C. Hartshorne, A. P. Plantinga, and C. Dore are some of those who have formulated ontological proofs for God’s existence.
Descartes held that the idea of God is innate. Although Descartes distinguished the existence of a thing from its essence, he states with respect to God in the fifth meditation: “we cannot separate God’s essence from existence just as we cannot separate the essence of a triangle from the fact that the sum of its three angles equal to right angles, or the idea of a mountain from the idea of a valley. So we cannot think of God (i.e., the most perfect being) as lacking existence (and so as lacking a perfection), just as we cannot think of a mountain without a valley. […] from the fact that I cannot think of a mountain without a valley it does not follow that a mountain and a valley exist, only that a mountain and a valley are inseparable whether they exist or not. From the fact that God can only be thought of as existing, it follows that existence is inseparable from God, and therefore that He really exists, not because my thought causes this or that it could impose any necessity on anything, but on the contrary, because the necessity of the thing itself, i.e., the necessity of God’s existence, inclines me to think in this way. For I am unable to think of God without existence (i.e., a most perfect being without the highest perfect), in the same way I can imagine a horse with wings or without wings”.
Descartes seems to be right on the point that God’s existence cannot be separated from his essence. As St. Thomas Aquinas argues, God really is his own existence (S. th., I q. 3, a. 4) and therefore the proposition—“God exists”—is a self-evident proposition (propositio per se nota) (ibid., I, q. 2, a. 1). The problem, however, is to demonstrate that God is his own existence. As Thomas observes, the propostion “God exists” is evident in itself, but not for us (ibid., I, q. 2, a. 1).
The so-called ontological (a priori) proofs of God’s existence are based on the premise that in one single case, namely with respect to God, we may infer from the concept of “God” that God exists. Really, if it is known that in God essence and existence are the same, then from the content of the concept “God” we may infer that God exists. It must first be known, however, that God is his own existence, but then there would be no need to prove what is already known, namely that God exists. If, however, one accepts God thus understood only as a possibility (as non-contradictory) then from possible states the proposition that God really exists cannot be inferred.
R. Descartes, Meditationes de prima philosophiae, P 1641 (Medytacje o pierwszej filozofii [Meditations on first philosophy], Wwa 1958, I 90–91); É. Gilson, Sens et nature de l’Argument de S. Anselme, AHDLMA 9 (1934), 6–51; M. Gogasz, Problem istnienie Boga u Anzelma z Canterbury i problem prawdy u Henryka z Gendawy [The problem of God’s existence in Anselm of Canterbury and the problem of truth in Henry of Ghent], Lb 1961, 7–72; idem, O nowszych badaniach dowodu ontologicznego Anzelma z Canterbury [On more recent investigations of the ontological proof of Anselm of Canterbury], RF 11 (1963) z. 1, 103–111; C. Hartshorne, Anselm’s Discovery. A Re- Examination of the Ontological Proof for God’s Existence, La Salle 1965; The Ontological Argument from Anselm to Contemporary Philosophers, NY 1965; S. Kowalczyk, Filozofia Boga, Lb 1972, 19954, 231–240; C. Hartshorne, The Logic of Pefection and Other Essays in Neoclassical Metaphysics, La Salle 19733; J. L. Mackie, The Miracle of Theism: Arguments for and against the Existence of God, Ox 1983 (Cud teizmu. Argumenty za istnieniem Boga i przeciw istnieniu Boga [The miracle of theism. Arguments for the existence of God and against the existence of God], Wwa 1997, 53–81); C. Dore, Theism, Dor 1984; J. Seifert, Si Deus est Deus, Deus est. Refleksje nad dowodem ontologiczum Ŷw. Anzelma w interpretacji Ŷw. Bonawentury [Si Deus est Deus, Deus est. Reflections on the ontological proof of St. Anselm in the interpretation of St. Bonaventure], ZNKUL 28 (1984) n. 1, 15–28; Anzelm z Canterbury [Anselm of Canterbury] Monologion. Proslogion, Wwa 1992, 145–146; A. C. Plantinga, Bóg, wolnoŶć i zło, Kr 1995, 125–161; D. Lewis, Anzelm i rzeczywistoŶć [Anselm and reality], in: B. Chedeńchuk, Filozofia religii [Philosophy of religion], Wwa 1997, 123–138; N. Nalcolm, Argumenty ontologiczne Anzelma [Anselm’s ontological arguments], in: ibid., 101–121; T. Grzesik, A New Look at the “ratio Anselmi” of the “Proslogion”, in Saint Anselm, Bishop and Thinker, Lb 1999, 225–233.