Srećko Kovač

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.

Logical reasoning is not only a component of religious faith (cf., for instance, the "Golden rule"), but, in addition, the religious faith itself can be conceived as a logical pragmatic function applied to sentences and their meanings. Pragmatic role of religious faith is shown on the examples of the analogy of seed and spoken word (e.g., Mt 13:3-23) and on the degrees of faith described in the episode about Nicodemus (John 3). Pragmatics adds (different grades of) perseverance to the correctness of reasoning and to the truth-preservation of the consequence relation. Correspondingly, religious faith is described by formally defined model and satisfaction relation, which are applied to and examined on the text of John 3.

A first-order logic of belief with identity is proposed, primarily to give an account of possible de re contradictory beliefs, which sometimes occur as consequences of de dicto non-contradictory beliefs. A model has two separate, though interconnected domains: the domain of objects and the domain of appearances. The satisfaction of atomic formulas is defined by a particular S-accessibility relation between worlds. Identity is non-classical, and is conceived as an equivalence relation having the classical identity relation as a subset. A tableau system with labels, signs, and suffixes is defined, extending the basic language $\mathscr{L}_{\mathbf{QB}}$ by quasiformulas (to express the denotations of predicates). The proposed logical system is paraconsistent since $\phi \wedge \neg\phi$ does not ``explode'' with arbitrary syntactic consequences.

The paper sets out from Göodel's question about primitive concepts, in connection with Gödel's proposal of the employment of phenomenological method. The author assumes that the answer that can be found in Kant is relevant as a starting point. In a modification of the approach by K. Reich, a reconstruction of Kant's "deduction'' of logical forms of judgment is presented, which serve Kant as the basis for his "metaphysical deduction of categories'' including substantiality and causality. It is proposed that different aspects of Kant's "original unity of self-consciousness'' as applied and attached to concrete representations step by step yield different forms of concepts, judgments, and inferences. Categorical, hypothetical and disjunctive judgments are shown to be gradually strengthening the conditions of bringing our representations under the "objective unity of consciousness", and in this way gradually implementing logical laws. The corresponding concepts of substantiality, causality, and mutual influence appear to be grounded in the primitive forms of our thinking.

Aristotelian causal theories incorporate some philosophically important features of the concept of cause, including necessity and essential character. The proposed formalization is restricted to one-place predicates and a finite domain of attributes (without individuals). Semantics is based on a labeled tree structure, with truth defined by means of tree paths. A relatively simple causal prefixing mechanism is defined, by means of which causes of propositions and reasoning with causes are made explicit. The distinction of causal and factual explanation are elaborated, and examples of cyclic and convergent causation are given. Soundness and completeness proofs are sketched.

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.

We want to show that Aristotle’s general conception of syllogism includes as its essential part the logical concept of necessity, which can be understood in a causal way. This logical conception of causality is more general then the conception of the causality in the Aristotelian theory of proof (“demonstrative syllogism”), which contains the causal account of knowledge and science outside formal logic. Aristotle’s syllogistic is described in a purely intensional way, without recourse to a set-theoretical formal semantics. It is shown that the conclusion of a syllogism is justified by the accumulation of logical causes applied during the reasoning process. It is also indicated that logical principles as well as the logical concept of causality have a fundamental ontological role in Aristotle’s “first philosophy”.

Kant's theory of transcendental ideas can be conceived as a sort of model theory for an empirical first-order object theory. The main features of Kant's theory of transcendental ideas (especially its antinomies and their solutions) can be recognized, in a modified way, in a religious discourse as exemplified in the dialogue of Jesus and the Samaritan woman (John 4). In this way, what is by Kant meant merely as regulative ideas obtains a sort of objective reality and becomes a religiously founded metaphysics. A metaphysical theory of religious dialogue is formalized on the basis of an extended justification logic of evidence and wish agents.

There is a long tradition of logic, from Aristotle to Gödel, of understanding a proof from the concepts of necessity and causality. Gödel's attempts to define provability in terms of necessity led him to the distinction of formal and absolute (abstract) provability. Turing's definition of mechanical procedure by means of a Turing machine (TM) and Gödel's definition of a formal system as a mechanical procedure for producing formulas prompt us to understand formal provability as a mechanical causality. We propose a formalism which makes explicit the mechanical causal nature of a TM's work. We claim that Gödel's axiomatised ontotheology and his ontological proof give a clue for the understanding of the concept of absolute provability and the pattern of the corresponding absolute completeness proof, respectively.

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.

[English in PhilArchive, unpublished]. Ruđer Bošković's (Rogerius Joseph Boscovich, 1711-1787) induction is described as a reasoning procedure that combines abductive, generalizing and deductive forms of inference. According to Bošković, the application of inductive reasoning extends beyond natural science. Bošković's critique of the use of the principle of sufficient reason is discussed, and constructive rules of Bošković's inductive logic are proposed from the standpoint of contemporary justification logic. To that end, justification logic could be extended with Bošković's typology of reasons. Hunter's result (1965) is conceived as a confirmation that the inference from the constructive defectus rationis is a necessary component of Bošković's induction. - English version in _PhilArchive_.

The book is a collection of papers addressing the role of logic in forming and developing philosophy. In particular, on the ground of modern development of logic, it is shown that philosophy can be established (and, in fact, to a large extent is established) as a modern science. The following problems are addressed: general relationship between philosophy and science (especially from a logical viewpoint); the use of logic in ordinary language; names and descriptions; Quine's pragmatic extensional Platonism and predicate-functor logic; philosophical and logical aspects of Gödel's onto-theological system. In the last two chapters, an early critique and emendement of algebraic logic by Croatian philosophers Franjo Marković and Mate Meršić, respectively, is examined.

We show how some model-theoretical devices (local reasoning, modes of presentation, an additional accessibility relation) can be combined in first-order modal logic to formalize the consequence relation that includes de dicto and de re contradictory beliefs. Instead of special ``sense objects'', appearances of objects in an agent's belief are introduced and presented as ordered pairs consisting of an object and an individual constant. A non-classical identity relation is applied. A relation S on the set of possible worlds is introduced, which models possible distortions in an agent's picture of a (real) world. The application of such models in deontic logic is illustrated by a characteristic example.

On the ground of Kant’s reformulation of the principle of con- tradiction, a non-classical logic KC and its extension KC+ are constructed. In KC and KC+, \neg(\phi \wedge \neg\phi), \phi \rightarrow (\neg\phi \rightarrow \phi), and \phi \vee \neg\phi are not valid due to specific changes in the meaning of connectives and quantifiers, although there is the explosion of derivable consequences from {\phi, ¬\phi} (the deduc- tion theorem lacking). KC and KC+ are interpreted as fragments of an S5-based first-order modal logic M. The quantification in M is combined with a “subject abstraction” device, which excepts predicate letters from the scope of modal operators. Derivability is defined by an appropriate labelled tableau system rules. Informally, KC is mainly ontologically motivated (in contrast, for example, to Jaśkowski’s discussive logic), relativizing state of affairs with respect to conditions such as time.

The first beginnings of modern logic in Croatia are recognizable as early as in the middle of the 19th century in Vatroslav Bertić. At the turn of the 20th century, Albin Nagy, who was teaching in Italy, made contributions to algebraic logic and to the philosophy of logic. At that time, a distinctive author Mate Meršić stood out, also working on algebraic logic. In the Croatian academic philosophy, until the publication of Gajo Petrović's textbook (1964) and the contributions by Heda Festini, a critical or indifferent attitude toward modern logic prevailed. The first comprehensive modern logic textbook in Croatian was written by mathematician Vladimir Devidé (1964), known, for example, for his axiomatizations of natural numbers and classical propositional logic. In the Croatian philosophy of the 1980s and 1990s, influential logicians are Goran Švob and mathematician Zvonimir Šikić. At the turn of the 21st century, logical investigations are being intensified and extended to various branches of the contemporary logic.

The criticism of Hilbert's axiomatic system of geometry by Mate Meršić (Merchich, 1850-1928), presented in his work "Organistik der Geometrie" (1914, also in "Modernes und Modriges", 1914), is analyzed and discussed. According to Meršić, geometry cannot be based on its own axioms, as a logical analysis of spatial intuition, but must be derived as a "spatial concretion" using "higher" axioms of arithmetic, logic, and "rational algorithmics." Geometry can only be one, because space is also only one. It cannot be reduced to manipulation with symbols but has to deal with concepts and provide real knowledge. According to Meršić, aiming at some particular proof of the consistency of the whole axiomatic system is meaningless because the consistency follows from the truth of individual axioms based on spatial intuition. It is impossible, according to Meršić, for the geometric axioms to be mutually independent because they must be interconnected as essential parts of a whole. Although Meršić did not recognize all the advantages of Hilbert's formalization of geometry, he clearly pointed out some crucial limitations of the axiomatic method.

The paper aims to show that by abstracting from a specific mythical historical- stylistic context and “ideation” of the notion of the Proto-Slavic deities Perun and Veles, especially in Croatian tradition, symbolic archetypes and abstract notions of form and primordial matter (materia prima) can be extracted from mythical content. We refer to mythical texts and contents according to the reconstructions and materials brought by Radoslav Katičić, and comparative analysis by Mislav Ježić. We distinguish form (1) as that in which identity and possibility of a thing consists, (2) as the reasonableness of judgment and the form of existence, and (3) as the specific structure of a thing, which unites its parts and aspects as a whole and constitutes its internal necessity. These formative notions are relativized and nullified in Veles’ appearances, in which the archetypal notion of primordial matter is encoded. Examples of Platō’s dialogues historically confirm certain aspects of decoding myth as constitutive of philosophy. The above approach also opens a view of the roots of Croatian philosophical thought, which in its genesis can be traced back to Proto-Slavic mythical archetypes. With the implementation of Christianity, the questions of identity, reason and the structure of the whole are raised radically and sharply, as shown by the text of Trpimir’s grant (852).

The Aristotelian origins of formal systems are outlined, together with Aristotle's use of causal terms in describing syllogisms. The precision and exactness of a formalism, based on the projection of logical forms into perceptive signs, is contrasted with foundational, abstract concepts, independent of any formalism, which are presupposed for the understanding of a formal language. The definition of a formal system by means of a Turing machine is put in the context of Wittgenstein's general considerations of a machine understood as a sign. A modification of Łukasiewicz's logic Ł3 with the inclusion of justification terms is proposed in order to formally analyse some features of formalistic reasoning as a mechanical, causal affair within a wider context of "indeterminacy".

A close interrelationship between logic and religious faith is confirmed in many places of the Bible. In the paper, special attention is paid to the dialogue of Jesus and a Samaritan woman (John 4). In a proposed outline of a logical formalization, religious faith is described as a pragmatic function through which the linguistic and logical content is contextually realized. In the continuation of the paper, Gödel's ontological proof is commented, which in a logically rigorous way describes the ontology where we can detect the systematic place of religious faith as an ontological force.

The structure "home - world - ideals" is presented as the structure of "philosophical striving" (F. Marković). It could be formally described as a model consisting of a domain, relations and a valuation. On that basis, the identity, openness, and the significance of Croatian philosophy is investigated. The programme of the renewal of Croatian philosophy (as proposed 1882 by Franjo Marković) is re-examined, and some unsolved historical-cultural discontinuities within the programme are described. The written beginnings of Croatian philosophical thought are detected in the Charter of Duke Trpimir (852).

The reception of Kant began in Croatia at the turn of the 19th century with the writings of J.B. Horváth, whose textbooks were in use at that time in Croatia and Hungary. Unlike Horváth's decidedly negative attitude toward Kant, Šimun Čučić (Simeon Chuchich), in his systematic work Philosophia Critice Elaborata (1815), adopted some aspects of Kantian philosophy. This includes, for example, the formalistic conception of logic, Kantian apriorism and subjectivism, the formalistic approach to the moral law, and the like. However, since these elements were incorporated into a schoolbook type of text, they could not always be consistently implemented. The beginning of the reception of Kant in Croatia coincided with the revival of Croatian national self-awareness. -- Die Kantrezeption setzte in Kroatien an der Wende zum 19. Jahrhundert ein mit den Schriften J. B. Horváths, dessen Lehrbuecher in Kroatien und Ungarn damals in Gebrauch waren. Im Unterschied zu Horváth's ausgeschprochen negativer Einstellung zu Kant hat Šimun Čučić in seinem systematischen Werk Philosophia critice elaborata (1815) einige Aspekte der Kantischen Philosophie uebernommen. Dies betrifft z.B. die formalistische Auffassung der Logik, die Uebernahme des kantianischen Apriorismus und Subjektivismus, die formalistische Auffassungsweise des moralischen Gesetzes und dgl. Da nun diese Momente in ein schulmaeßig konzipiertes Buch aufgenommen wurden, konnten sie nicht immer konsequent durchgefuehrt werden. Der Beginn der Kantrezeption in Kroatien koinzidierte mit der Wiedererweckung des kroatischen nationalen Selbsbewußtseins.

The basic principles of Cipra's metaphysics (according to his book "Metamorphoses of Metaphysics") are analyzed with respect to Cipra's request for the revision of classical logical principles (of identity, excluded middle and contradiction). In Cipra's metaphysics, the principle of identity holds for being, necessity and past only, the principle of excluded middle does not hold for coming-to-be, possibility and present, and the principle of contradiction does not hold for the actuality, reality (freedom) and future. A propositional and first-order temporal model and semantics are defined for such a concept of metaphysical time. The propositional ockhamistic branching time model is extended, in a first-order model, with a non-empty set of object shapes and an equivalence relation between object shapes in time, so that, for example, different, previously equivalent object shapes can in future contradict one another.

Different forms and transformations of philosophy in the modern world are analyzed according to the view of the Croatian philosopher Vanja Sutlić (1925-1989). A key aspect is the "realization of philosophy" in "work science", which encompasses the entire "world of work" established in modern times. This universal and real science is also an important precondition for "historical thinking". The uniformity of this science, problematized by Sutlić, can be found today in refined logical and semantic structures, which allow for a renewed and richer articulation of philosophical concepts than was traditionally possible.

This paper proposes a possible reconstruction and philosophical-logical clarification of Gödel's idea of causality as the philosophical fundamental concept. The results are based on Gödel's published and non-published texts (including Max Phil notebooks), and are established on the ground of interconnections of Gödel's dispersed remarks on causality, as well as on the ground of his general philosophical views. The paper is logically informal but is connected with already achieved results in the formalization of a causal account of Gödel's onto-theological theory. Gödel's main causal concepts are analysed (will, force, enjoyment, God, time and space, life, form, matter). Special attention is paid to a possible causal account of some of Gödel's logical concepts (assertion, privation, affirmation, negation, whole, part, general, particular, subject, predicate, necessary, possible, implication), as well as of logical antinomies. The problem of mechanical and non-mechanical procedures in the work with and on concepts is addressed in terms of Gödel's causal view.

Quine rejects intensional Platonism and, with it, also rejects attributes (properties) as designations of predicates. He pragmatically accepts extensional Platonism, but conceives of classes as merely auxiliary entities needed to express some laws of set theory. At the elementary logical level, Quine develops an “ontologically innocent” logic of predicates. What in standard quantification theory is the work of variables is in the logic of predicates the work of a few functors that operate on predicates themselves: variables are eliminated. This “predicate functor logic” may be conceived as a peculiar sort of Platonism - ontologically neutral, reduced to schematized linguistic forms.

The article focuses on Kant's formal logic (formal theory of concepts, judgments, and inference, general methodology) in the systematic order of logical forms and presents the main characteristics of his transcendental logic (theory of categories and transcendental ideas). Kant's problem of the foundations of logic and its completeness is addressed. The relevance and influence of Kant's account of logic in the development of modern logic is outlined. The article gives a selection of primary and secondary sources.