The Ontological argument

"I am who I am" (Exodus 3:14)


The Ontological argument was formulated by Anselm, while he was the Abbot of Bec, in works such as De Veritate, De Libero Arbitrino, Monologion and Proslogion. Anselm was trying to find an argument that would be self-contingent and, hence, for its proof require nothing but itself.

In Proslogion the argument is that God is a being than which no greater can be thought, and if that being did not exist, a greater being could actually be thought of, and thus God must necessarily exist. In chapter 15 Anselm even argued that God must be greater than that which no greater can be thought. Let's call that being T from now on. Formally Anselm's argument can be stated this way:

  1. When someone thinks of T, that being exists in his mind.
  2. If T does not exist in reality as well as in the mind, then T is not T, since there exists something greater, and that greater thing can be thought of.
  3. But if T = T, then T exists in reality as well.
  4. Thus God must necessarily exist.


It may not be very easy at first sight to put the finger on the fallacy of this argument, but a little thinking and reading revealed to me the following points. It is obvious from the objections that the Ontological argument has never been quite accepted by philosophers, and that it is the worst of all the classical "evidences" for christianity.

  1. Begging the question
  2. My immediate objection to this argument was that it begs the question. Only if one already sees God as the greatest being that exists can that person be convinced by the argument. Atheists don't believe there exists a being T, so for us the argument is not valid. This is exactly the same criticism that Thomas Aquinas expressed in his Summa Theologiae.
    "It cannot be argued that it actually exists, unless it is admitted that there really is something than which nothing greater can be thought; and it is precisely this that is not admitted by those who hold that God does not exist."

  3. What is greater than what can be thought of is unintelligible
  4. Aquinas greatest objection, however, was that since god is a being greater than which can be thought, we cannot have enough information of the nature of god to set up an ontological argument. No man has enough knowledge of god's nature to assert his presense from it.

  5. Contradiction in terms
  6. An objection that is Raised in George Smith's Atheism -- The Case Against God, is that "The Greatest that can be thought of" (or in his book: "A perfect being") is an ambigious statement. The greatest that can be thought of could as well be the greatest evil, or the greatest ignorant, as well as good or wise, being possible.

    Anselms argument is equally appliable to qualities which human beings consider negative as positive, e.g. if a being more ignorant then can be thought of does not exist, something more ignorant can actually be thought of, and hence the ultimate ignorant being must exist. If god is the greatest that can be thought of he must be so in both the positive and the negative senses. Thus god as defined in the ontological argument is a contradiction in terms.

  7. Greatest what? And how?
  8. Redefining the greatest to imply the greatest in all positive aspects, but not in the negative, does not solve this problem. What is positive and negative is not the same for all people. Thus the argument will be different for different people. For example: I consider honesty, truth and sceptisism to be three of the highest virtues, while many christians would say that dishonesty, lies and blind faith are virtues, if they leed to the salvation of more people. For me and them "the highest good" would not be the same. A logical argument about ultimate reality must be the same for all people, and hence the argument is invalid.

  9. The first premise is unsound
  10. The first premise that "When someone thinks of T that being exists in his mind" was demonstrated to be invalid by Gregory of Rimin. If it had been correct, then the following statement would be equally true: "What cannot be thought can be thought", which is a self-contradiction.

    We can understand the sentence "a greater than that than which a greater cannot be thought", but it does not necessary follow from that that the subject exists in our minds, and we cannot understand the being that is greater than that than which a greater cannot be thought. This argument is in line with the one of Aquinas above, because if god is greater than what can be thought, how can we assert his existence from what we know?

  11. The second premise is unsound
  12. As Bertrand Russell showed in his Introduction to Mathematical Philosophy, the argument is based on a mistaken view of existence. It is important to distinguish between things described and things named, and existence can only be asserted for something described. The world of ideas is not necessarily the same as the real world, and thus it is useless to say from "This is T" and "T exists" that "This exists".
    "The proposition 'The so-and-so exists' is significant, whether true or false; but if a is the so-and-so (where 'a' is a name), the words 'a exists' are meaningless. It is only of descriptions -- definite or indefinite -- that existence can be significantly asserted; for, if 'a' is a name it must name something: what does not name anything is not a name, and therefore, if intended to be a name, is a symbol devoid of meaning." -- Bertrand Russell (Russell, 1919, p179)
    The best illustration of this is perhaps this pseudo-syllogism: "Men exist, Socrates is a man, therefore Socrates exists". Since Socrates is dead, it is obvious from this analogy that the second premise of the Ontological argument fails. Another example is: "The author of the Illiad exists, Homer was the author of the Illiad, therefore Homer exists"

  13. The third premise is unsound
  14. The function God = God is not necessarily true. This is also best illustrated with an example. To say that the present king of France = the present king of France is false, since there is no king in the republic of France. The function T = T is only true if T really exists, and thus the third premise in Anselms Ontological argument is not valid unless God is already presupposed to exist. On this ground William of Ockham (Latinized as Occam) dismissed the Ontological argument.

  15. Existence is no predicate
  16. A critique closely related to that of Russell was Kant's objection that existence is not a characterizing predicate. A hundred imaginary gold coins have the same qualities as a hundred real ones. We can also speak of a house, for instance, and describe it as yellow, two floors high, etc, but it makes no sense to say "and it also exists".


The Ontological argument begs the question, its premises are unsound and contradictory, and it fails to distinguish between descriptions, names and predicates. Neither are we able to define what is ment with "The greatest being possible". The Ontological argument has been dismissed over and over again, and even if the argument could be expressed in a different way, it would still fail since we could never achive enough knowledge of god through introspection to be able to assert his existence.


  1. Anders Aspegren, Finns Gud?, Human-Etiska Förbundets småskrift Nr 14.
  2. Anders Aspegren, Religionsboken -- En motskrift om giftet som förvränger, Human-Etiska Förbundets småskrift Nr 4.
  3. Bertrand Russell, Introduction to mathematical philosophy, George Allen & Unwin, Ltd., London, 1919.
  4. Bertrand Russell, History of Western Philosophy, George Allen & Unwin, Ltd., London, 1945.
  5. Julius R. Weinberg, Ockham, Descartes, and Hume, The University of Wisconsin Press, 1977.

Mi casa Back to Fredrik Bendz' homepage
Created: December 8, 1996
Last update: Saturday, December 12, 1998

© Fredrik Bendz
S-mail :  here
E-mail :