Ontological Arguments
Ontological arguments are arguments, for the conclusion that God exists, from premises which are supposed to derive from some source other than observation of the world e.g., from reason alone. In other words, ontological arguments are arguments from nothing but analytic, a priori and necessary premises to the conclusion that God exists.
The first, and best-known, ontological argument was proposed by St. Anselm of Canterbury in the 11th. century A.D. In his Proslogion, St. Anselm claims to derive the existence of God from the concept of a being than which no greater can be conceived. St. Anselm reasoned that, if such a being fails to exist, then a greater being namely, a being than which no greater can be conceived, and which exists can be conceived. But this would be absurd: nothing can be greater than a being than which no greater can be conceived. So a being than which no greater can be conceived i.e., God exists.
In the seventeenth century, Ren Descartes defended a family of similar arguments. For instance, in the Fifth Meditation, Descartes claims to provide a proof demonstrating the existence of God from the idea of a supremely perfect being. Descartes argues that there is no less contradiction in conceiving a supremely perfect being who lacks existence than there is in conceiving a triangle whose interior angles do not sum to 180 degrees. Hence, he supposes, since we do conceive a supremely perfect being we do have the idea of a supremely perfect being we must conclude that a supremely perfect being exists.
In the early eighteenth century, Gottfried Leibniz attempted to fill what he took to be a shortcoming in Descartes' view. According to Leibniz, Descartes' arguments fail unless one first shows that the idea of a supremely perfect being is coherent, or that it is possible for there to be a supremely perfect being. Leibniz argued that, since perfections are unanalysable, it is impossible to demonstrate that perfections are incompatible and he concluded from this that all perfections can co-exist together in a single entity.
In more recent times, Kurt Gödel, Charles Hartshorne, Norman Malcolm and Alvin Plantinga have all presented much-discussed ontological arguments which bear interesting connections to the earlier arguments of St. Anselm, Descartes and Leibniz. Of these, the most interesting are those of Gödel and Plantinga; in these cases, however, it is unclear whether we should really say that these authors claim that the arguments are proofs of the existence of God.
Critiques of ontological arguments begin with Gaunilo, a contemporary of St. Anselm. Perhaps the best known criticisms of ontological arguments are due to Immanuel Kant, in his Critique of Pure Reason. Most famously, Kant claims that ontological arguments are vitiated by their reliance upon the implicit assumption that "existence" is a predicate. However, as Bertrand Russell observed, it is much easier to be persuaded that ontological arguments are no good than it is to say exactly what is wrong with them. This helps to explain why ontological arguments have fascinated philosophers for almost a thousand years.
In various ways, the account provided to this point is rough, and susceptible of improvement. Sections 1 - 5 in what follows provide some of the requisite embellishments, though as is usually the case in philosophy there are many issues taken up here which could be pursued at much greater length. Sections 6 - 8 take up some of the central questions at a slightly more sophisticated level of discussion:
1. History of Ontological Arguments 2. Taxonomy of Ontological Arguments 3. Characterisation of Ontological Arguments 4. Objections to Ontological Arguments 5. Parodies of Ontological Arguments 6. Gödel's Ontological Argument 7. Plantinga's Ontological Argument 8. St. Anselm's Ontological Argument Bibliography Other Internet Resources Related Entries
1. History of Ontological Arguments
1078:
St. Anselm, Proslogion. Followed soon after by Gaunilo's critique In Behalf of the Fool.
1264:
St. Thomas Aquinas, Summa. Criticises an argument which somehow descends from St. Anselm.
1637:
Descartes, Meditations. The Objections particularly those of Caterus and Gassendi and the Replies contain much valuable discussion of the Cartesian arguments.
c1680:
Spinoza, Ethics. Intimations of a defensible mereological ontological argument, albeit one whose conclusion is not (obviously) endowed with religious significance.
1709:
Leibniz, New Essays Concerning Human Understanding. Contains Leibniz's attempt to complete the Cartesian argument by showing that the Cartesian conception of God is not inconsistent.
1776:
Hume, Dialogues Concerning Natural Religion. Part IX is a general attack on a priori arguments (both analytic and synthetic). Includes a purported demonstration that no such arguments can be any good.
1787:
Kant, Critique of Pure Reason. Contains famous attack on traditional theistic arguments. Three objections to "the ontological argument", including the famous objection based on the dictum that existence is not a predicate.
1831:
Hegel, Lectures of 1831. Famous assertion uncontaminated by argument of the correctness of ontological arguments.
1884:
Frege, Foundations of Arithmetic. Existence is a second-order predicate. First-order existence claims are meaningless. So ontological arguments whose conclusions are first-order existence claims are doomed.
1941:
Hartshorne, Man's Vision of God. Defence of modal ontological arguments, allegedly derived from Proslogion 3.
1960:
Malcolm, "Anselm's Ontological Argument". Defence of modal ontological arguments by a famous ordinary philosopher.