Ontological arguments like those of Gödel (1995) and Pruss (2009; 2012) rely on premises that initially seem plausible, but on closer scrutiny are not. The premises have modal import that is required for the arguments but is not immediately grasped on inspection, and which ultimately undermines the simpler logical intuitions that make the premises seem plausible. Furthermore, the notion of necessity that they involve goes unspecified, and yet must go beyond standard varieties of logical necessity. This leaves us little reason (...) to believe the premises, while their implausible existential import gives us good reason not to. (shrink)

A universal reasoning approach based on shallow semantical embeddings of higher-order modal logics into classical higher-order logic is exemplarily employed to analyze several modern variants of the ontological argument on the computer. Several novel findings are reported which contribute to the clarification of a long-standing dispute between Anderson and Hájek. The technology employed in this work, which to some degree realizes Leibniz’s dream of a characteristica universalis and a calculus ratiocinator for solving philosophical controversies, is ready to be fruitfully adopted (...) in larger scale by philosophers. (shrink)

This paper presents detailed formalizations of ontological arguments in a simple modal natural deduction calculus. The first formal proof closely follows the hints in Scott’s manuscript about Gödel’s argument and fills in the gaps, thus verifying its correctness. The second formal proof improves the first one, by relying on the weaker modal logic KB instead of S5 and by avoiding the equality relation. The second proof is also technically shorter than the first one, because it eliminates unnecessary detours and uses (...) Axiom 1 for the positivity of properties only once. The third and fourth proofs formalize, respectively, Anderson’s and Bjørdal’s variants of the ontological argument, which are known to be immune to modal collapse. (shrink)

The paper shows that it is possible to obtain a "slingshot" result in Gödel's theory of positiveness in the presence of the theorem of the necessary existence of God. In the context of the reconstruction of Gödel's original "slingshot" argument on the suppositions of non-Fregean logic, this is a natural result. The "slingshot" result occurs in sufficiently strong non-Fregean theories accepting the necessary existence of some entities. However, this feature of a Gödelian theory may be considered not as a trivialisation, (...) but as an intended consequence of Gödel's ontotheological views. (shrink)

This paper aims to show that Godel's ontological argument can be parodied in much the same kind of way in which Gaunilo parodied Anselm's Proslogion argument. The parody in this paper fails; there is a patch provided in "Reply to Gettings" (Analysis 60, 4, 2000, 363-7).

St Anselm (1033-1109) devised an ontological “proof” of the existence of God based on the impossibility of conceiving of God's non-existence. This famous argument inspired a much less-widely known atheistic ontological “proof” of God's non-existence by Melbourne philosopher Douglas Gasking (1911-1994). Juxtaposing Gasking’s argument for the non-existence of God with Anselm’s “proof” brings the basic defect of Anselm’s argument into sharp relief.

Latest version of my SEP entry on ontological arguments, which first appeared in 1996. General discussion of ontological arguments. Includes a brief historical overview, a taxonomy of different kinds of ontological arguments, a brief survey of objections to the different kinds of ontological arguments identified in the taxonomy, and more extended discussions of Anselm's ontological argument (Proslogion 2), Godel's ontological argument, and Plantinga's ontological argument.

After introductory reminder of and comments on Gödel’s ontological proof, we discuss the collapse of modalities, which is provable in Gödel’s ontological system GO. We argue that Gödel’s texts confirm modal collapse as intended consequence of his ontological system. Further, we aim to show that modal collapse properly fits into Gödel’s philosophical views, especially into his ontology of separation and union of force and fact, as well as into his cosmological theory of the nonobjectivity of the lapse of time. As (...) a result, modal collapse should not be conceived in Gödel so much as a deficit, but rather as a kind of the rise of modalities to the “perfect” being. We further show that, in accordance with Gödel’s ontology, the concepts of modality and time should be derived in terms of the “fundamental philosophical concept” of cause. To give an example of how a formalization of such causative Gödelian ontology and ontological proof might look, we propose the transformation of GO into a kind of causally re-interpreted justification logic. (shrink)

This paper discusses recent work on higher-order ontological arguments, including work on arguments due to Gödel, Maydole and Pruss. After setting out a range of these arguments, the paper seeks to highlight the principal difficulties that these kinds of arguments confront. One important aim of the paper is to cast light on Gödel's ontological argument by way of an examination of a range of related higher-order arguments.

We describe a KB Gödelian ontological system, and some other weak systems, in a fully formal way using theory of types and natural deduction, and present a completeness proof in its main and specific parts. We technically and philosophically analyze and comment on the systems (mainly with respect to the relativism of values) and include a sketch of some connected aspects of Gödel's relation to Kant.

Amidst the array of criticisms levied against Kurt Gödel’s ontological proof, the critique by Randolph Rubens Goldman stands out for its unique emphasis on a hitherto overlooked yet pivotal weakness within the proof – its lack of an adequate applied semantics. Goldman’s perspective underscores a significant need: the connection of axioms, definitions, and theorems in the proof with the intended meanings of properties traditionally ascribed to God. However, as Goldman has shown, this attempt poses formidable challenges. The endeavour to establish (...) such a connection renders numerous sentences under the natural language interpretation of the proof meaningless, thus undermining the principle of bivalence. In this article, we analyse different methods to confront this problem. Our final solution is inspired by Bertrand Russell’s theory of definite descriptions: namely, we suggest construing sentences under the natural language interpretation of Gödel’s proof as conjunctions of formulas. In this way, we can eliminate meaningless sentences and uphold the once unsettled principle of bivalence. (shrink)

Philosophy Compass, Volume 17, Issue 7, July 2022.

Many versions of the ontological argument have two shortcomings: First, despite the arguments put forward, for example, by Hugh Chandler and Nathan Salmon, they assume that S5 is the correct modal logic for metaphysical modality. Second, despite the classical arguments put forward, for example, by David Hume and Immanuel Kant or the more recent arguments put forward, for example, by John Findlay and Richard Swinburne, they assume that necessary existence is possible. The aim of the paper is to develop an (...) alternative version of the ontological argument that, by an appeal to the logic of ‘actually’, avoids these two shortcomings. The version helps to leave aside unnecessary debates about the modal logic S5 or about the possibility of necessary existence and to focus on the actual challenge for the debate about the ontological argument: the challenge to evaluate the claim that it is possible that God exists. (shrink)

In this paper, I present what I call the symmetry conception of God within 1st order, extensional, non-well-founded set theory. The symmetry conception comes in two versions. According to the first, God is that unique being that is universally symmetrical with respect to set membership. According to the second, God is the universally symmetrical set of all sets that are universally symmetrical with respect to set membership. I present a number of theorems, most importantly that any universally symmetrical set is (...) identical to its essence, that show that the two symmetry conceptions intersect with some dominant theological conceptions of God. The theorems also show that both of the symmetry conceptions of God entail that God has a fractal like structure. (shrink)

Gödel’s ontological proof is by now well known based on the 1970 version, written in Gödel’s own hand, and Scott’s version of the proof. In this article new manuscript sources found in Gödel’s Nachlass are presented. Three versions of Gödel’s ontological proof have been transcribed, and completed from context as true to Gödel’s notes as possible. The discussion in this article is based on these new sources and reveals Gödel’s early intentions of a liberal comprehension principle for the higher order (...) modal logic, an explicit use of second-order Barcan schemas, as well as seemingly defining a rigidity condition for the system. None of these aspects occurs explicitly in the later 1970 version, and therefore they have long been in focus of the debate on Gödel’s ontological proof. (shrink)

First, I suggest that it is possible to make some further improvements upon the Gödelian ontological arguments that Pruss develops. Then, I argue that it is possible to parody Pruss's Gödelian ontological arguments in a way that shows that they make no contribution towards 'lowering the probability of atheism and raising the probability of theism'. I conclude with some remarks about ways in which the arguments of this paper can be extended to apply to the whole family of Gödelian ontological (...) arguments. (shrink)

Gödel's ontological argument is a formal argument for a being defined in terms of the concept of a positive property. I shall defend several versions of Gödel's argument, using weaker premises than Anderson's (1990) version, and avoiding Oppy's (1996 and 2000) parody refutations.

The article is devoted to Gödel's Ontological Argument, its place in the history of philosophy, and the current debate over the validity of Ontological Proof. First, we argue that Gödel's argument is a necessary step in the history of the development of Ontological Proof. Second, we show that Gödel's argument is based on implausible axiological principles, but can be appropriately reformulated in terms of plausible axiological principles. Also, we consider the debate over the validity of Gödel`s argument between contemporary neo-Gaunilist (...) Graham Oppy and the advocate of Gödel`s Ontological Proof Michael Gettings. We conclude that Gödel's Ontological Argument is immune to Oppy`s neo-Gaunilism. Finally, given the fact that Oppy`s parody is arguably the most fine-grained Gaunilo-style argument in the history of philosophy, we conclude that Gaunilist line of argumentation, even if successful in refuting Anselm`s Ontological Proof, does not work against Gödel's Ontological Argument. (shrink)

Truth is a value in that sense that a belief is correct just in case it is true, which is frequently expressed in the metaphor that beliefs aim at truth. But,what does it mean to say that beliefs aim at truth?There are three most prominent approaches to this issue:purposive(orcausal),teleological(orintentional), andnormative. A comprehensive discussion of these approaches is the goal of our article. We also offer the hierarchy of languages and meta-languages, which gives a fragmentary account of the concept of God’s (...) omniscience. (shrink)

The article is devoted to the interpretation of the ontological argument as a theoretical construction that is connected with understanding of the reflexive relationship of thinking and existence. The author concludes that the consistent implementation of this approach requires an appeal to the historically transitory forms of the ontological argument which reconstructs the logic of the evolution of reflexive systems. The ontological argument is considered as a developing theoretical construct. Therefore, theoretical constructs conceptualized as non-classical versions of the ontological argument (...) will constantly re-emerge. Emergence of the first non-classical version of the ontological argument is related to need of overcoming apriority of introduction of the idea of the absolute being which is typical for Cartesianism. This issue was realized in the Kantian doctrine of transcendental ideas, which presented mind as an independent essence that creates its own content. Thus, the metaphysical construction, conditionally referred to as “the moral proof of the existence of God,” is revealed in the paper as a non-classical variant of the ontological argument. However, while Kant could be content with faith in reality of other subjectivity as an object of moral action, Fichte’s scientific doctrine demanded a proof of objective reality of the concept of the other I. This issue was identical to a basic problem of an ontological argument. “The ontological argument of the other I” offered by Fichte was devoid of mysticism as it is indissolubly connected with the disclosure of the social nature of the human subjectivity. The last step in formation of the concept “non-classical version of the ontological argument” was taken in Hegelian philosophy, where the reflexive relations between the multitude of I’s were transformed to reflexive interconnection between God and man. The versions of ontological argument are considered in the paper as necessary stages which any theoretical model of reflexive systems has to pass in its formation. (shrink)

We claim that Kant's doctrine of the "transcendental ideal of pure reason" contains, in an anticipatory sense, a second-order theory of reality (as a second-order property) and of the highest being. Such a theory, as reconstructed in this paper, is a transformation of Kant's metatheoretical regulative and heuristic presuppositions of empirical theories into a hypothetical ontotheology. We show that this metaphysical theory, in distinction to Descartes' and Leibniz's ontotheology, in many aspects resembles Gödel's theoretical conception of the possibility of a (...) supreme being. The proposed second-order modal formalization of the Kantian doctrine of the "transcendental ideal" of the supreme being includes some specific features of Kantian general logic like "categorical", "hypothetical", and exclusive disjunctive propositions as basic forms. (shrink)

The aim of this paper is to prove strong completeness theorems for several Anderson-like variants of Gödels theory wrt. classes of modal structures, in which: (i). 1st order terms order receive only rigid extensions in the constant objectual 1st order domain; (ii). 2nd order terms receive non-rigid extensions in preselected world-relative objectual domains of 2nd order and rigid intensions in the constant conceptual 2nd order domain.

This article is a reply to Michael Gettings' criticisms of a previous paper of mine on Godel's ontological argument. (All relevant bibliographical details may be found in the article.) I provide a patch to my previous -- faulty -- attempt to provide a parody of Godel's ontological argument on the model of Gaunilo's parody of Anselm's Proslogion 2 argument.

Over the past decade, variants of Gödel's ontological arguments have been critically examined using modern symbolic AI technology. Computers have unearthed new insights about them and even contributed to the exploration of new, simplified variants of the argument, which now need to be further investigated by theologians and philosophers. In this article, I provide a brief, informal overview of these contributions and engage in a discussion of the possible future role of AI technology for the rigorous assessment of arguments in (...) theology and philosophy. (shrink)

Three variants of Kurt Gödel's ontological argument, proposed by Dana Scott, C. Anthony Anderson and Melvin Fitting, are encoded and rigorously assessed on the computer. In contrast to Scott's version of Gödel's argument the two variants contributed by Anderson and Fitting avoid modal collapse. Although they appear quite different on a cursory reading they are in fact closely related. This has been revealed in the computer-supported formal analysis presented in this article. Key to our formal analysis is the utilization of (...) suitably adapted notions of ultrafilters, and a careful distinction between extensions and intensions of positive properties. (shrink)

In the paper we introduce a wide range of Anderson-like variants of Gödel's theory and prove for each of them strong completeness theorem wrt. corresponding class of modal structures.These theories — all formulated in the 2nd order modal language with a 2nd order unary predicate of positiveness — differ among themselves with respect of: properties of the necessity operator and of the predicate of positiveness, axioms characterizing identity between 1st sort terms, definitions of identity between 2nd sort terms, the treatment (...) of Godlikeness as a term of the 2nd order, the treatment of necessary existence as a term of the 2nd order if there exists the necessity of its presence, the treatment of Ix (Ix(y) is read: terms x, y are identical), for every 1st sort term x, as a term of the 2nd order if there exists the necessity of its presence.Concerning to semantical commitments, the following are essential: (i) 1st order terms order receive only rigid extensions in the constant objectual 1st order domain; (ii) 2nd order terms receive non-rigid extensions in the constant objectual domain of 2nd order and rigid intensions in the constant conceptual 2nd order domain; (iii) The behavior of the identity between 1st sort terms shifts from possible worlds to possible worlds. (shrink)

Стаття присвячена онтологічному аргументу Курта Ґьоделя, його місцю в історії філософії і сучасних дебатах стосовно валідності онтологічного доказу. По-перше, ми аргументуємо що Ґьоделів аргумент є необхідним кроком в історії розвитку онтологічного аргументу. По-друге, ми показуємо, що Ґьоделів аргумент засновується на незадовільних аксіологічних принципах, проте може бути переформульований в термінах задовільних аксіологічних принципів. Також ми розглядаємо дебати щодо валідності Ґьоделевого аргументу між сучасним нео-ґаунілістом Ґремом Опі та захисником онтологічного аргументу Майклом Ґетінґсом. Ми доходимо висновку, що онтологічний аргумент Ґьоделя не вразливий до (...) ґаунілізму Опі. Нарешті, враховуючи той факт, що пародія Опі є, імовірно, найбільш досконалим аргументом ґаунілістського ґатунку в історії філософії, ми висновуємо, що ґаунілістська лінія аргументації, навіть якщо є успішною проти аргументу Ансельма, не працює проти аргументу Ґьоделя. (shrink)

Computational philosophy is the use of mechanized computational techniques to unearth philosophical insights that are either difficult or impossible to find using traditional philosophical methods. Computational metaphysics is computational philosophy with a focus on metaphysics. In this paper, we (a) develop results in modal metaphysics whose discovery was computer assisted, and (b) conclude that these results work not only to the obvious benefit of philosophy but also, less obviously, to the benefit of computer science, since the new computational techniques that (...) led to these results may be more broadly applicable within computer science. The paper includes a description of our background methodology and how it evolved, and a discussion of our new results. (shrink)

Anderson-like ontological proofs, studied in this paper, employ contingent identity, free principles of quantification of the 1st order variables and classical principles of quantification of the 2nd order variables. All these theories are strongly complete wrt. classes of modal structures containing families of world-varying objectual domains of the 1st order and constant conceptual domains of the 2nd order. In such structures, terms of the 1st order receive only rigid extensions, which are elements of the union of all 1st order domains. (...) Terms of the 2nd order receive extensions and intensions. Given a family of preselected world-varying objectual domains of the 2nd order, non-rigid extensions of the 2nd order terms belong always to a preselected domain connected with a given world. Rigid intensions of the 2nd order terms are chosen from among members of a conceptual domain of the 2nd order, which is the set of all functions from the set of worlds to the union of all 2nd order preselected domains such that values of these functions at a given world belong to a preselected domain connected with this world. (shrink)

Gödel's philosophical views were to a significant extent influenced by the study not only of Leibniz or Husserl, but also of Kant. Both Gödel and Kant aimed at the secure foundation of philosophy, the certainty of knowledge and the solvability of all meaningful problems in philosophy. In this paper, parallelisms between the foundational crisis of metaphysics in Kant's view and the foundational crisis of mathematics in Gödel's view are elaborated, especially regarding the problem of finding the “secure path of a (...) science” for both mathematics and philosophy. Gödel's temporal subjectivism and metaphysical conceptual objectivism are presented as positively or negatively motivated by Kant's viewpoints. A remark on Gödel's collapse of modalities (in accordance with the collapse of objective time) is added. (shrink)

A shallow semantic embedding of an intensional higher-order modal logic in Isabelle/HOL is presented. IHOML draws on Montague/Gallin intensional logics and has been introduced by Melvin Fitting in his textbook Types, Tableaus and Gödel’s God in order to discuss his emendation of Gödel’s ontological argument for the existence of God. Utilizing IHOML, the most interesting parts of Fitting’s textbook are formalized, automated and verified in the Isabelle/HOL proof assistant. A particular focus thereby is on three variants of the ontological argument (...) which avoid the modal collapse, which is a strongly criticized side-effect in Gödel’s resp. Scott’s original work. (shrink)

Classical higher-order logic, when utilized as a meta-logic in which various other logics can be shallowly embedded, is well suited for realising a universal logic reasoning approach. Universal logic reasoning in turn, as envisioned already by Leibniz, may support the rigorous formalisation and deep logical analysis of rational arguments within machines. A respective universal logic reasoning framework is described and a range of exemplary applications are discussed. In the future, universal logic reasoning in combination with appropriate, controlled forms of rational (...) argumentation may serve as a communication layer between humans and intelligent machines. (shrink)