Wojciech Krysztofiak

The main purpose of the paper concerns the question of the existence of hard mathematical facts as truth-makers of mathematical sentences. The paper defends the standpoint according to which hard mathematical facts do not exist in semantic models of mathematical theories. The argumentative line in favour of the defended thesis proceeds as follows: slingshot arguments supply us with some reasons to reject various ontological theories of mathematical facts; there are two ways of blocking these arguments: through the rejection of the principle of extensionality for individual terms or through the rejection of the principle of Wittgenstein; the first way cannot be accepted because it leads to the practice of softening mathematical facts; the second way, called fine-graining facts, cannot be accepted because it also results in the practice of softening facts. Hence, only soft mathematical facts can be introduced into semantic models of mathematical theories. Because they should be rather interpreted as mental representations of mathematical objects, they no longer satisfy the semantic role of truth-makers in relation to mathematical sentences. The argument formulated in the paper is based on the analysis of mathematical extensions of the basic non-Fregean logic. Sixty-two definitions of potential fact-identity connectives are also presented. The paper's conclusion may be interpreted as undermining the situational paradigm of building semantics for mathematical languages.

In this paper, a formal theory is presented that describes syntactic and semantic mechanisms of philosophical discourses. They are treated as peculiar language systems possessing deep derivational structures called architectonic forms of philosophical systems, encoded in philosophical mind. Architectonic forms are constituents of more complex structures called architectonic spaces of philosophy. They are understood as formal and algorithmic representations of various philosophical traditions. The formal derivational machinery of a given space determines its class of all possible architectonic forms. Some of them stand under factual historical philosophical systems and they organize processes of doing philosophy within these systems. Many architectonic forms have never been realized in the history of philosophy. The presented theory may be interpreted as falling under Hegel’s paradigm of comprehending cultural texts. This paradigm is enriched and inspired with Propp’s formal, morphological view on texts. The peculiarity of this modification of the Hegel-Propp paradigm consists of the use of algebraic and algorithmic tools of modeling processes of cultural development. To speak metaphorically, the theory is an attempt at the mathematical and logical history of philosophy inspired by the Internet metaphor. And that is why it belongs to the tradition of doing metaphilosophy in The Lvov-Warsaw School, which is continued today mainly by Woleński, Pelc, Perzanowski, and Jadacki.

The paper presents a new argument supporting the ontological standpoint according to which there are no mathematical facts in any set theoretic model (world) constructed on the grounds of second order arithmetical theories founded upon set theory. Slingshot arguments directed against facts, situations and other propositional entities are usually blocked by rejecting one of the main inference rules used in various versions of this argument. Authors distinguish two types of main inference rules used in these variants: (i) for non-propositional expressions: iota-conversion rules (ι-conv), iota-substitution rules (ι-subs), lambda-conversion principle (λ-conv); and (ii) for propositional expressions: the principle of substitutivity for logical equivalents (PSLE). Even if strategies for defending facts by the rejection of one of the mentioned rules are accepted, it may be shown that the acceptance of the requirement that mathematical facts (situations or truth-makers) differing with regard to their constituents are different facts, leads to the contradiction in meta-theories of set theoretic models for first order arithmetical theories. In the paper, a new type of slingshot argument is presented, which may be called hyper-slingshot . The difference between meta-theoretical hyper-slingshots and conventional slingshots consists in the fact that the former are formulated in the semantic meta-language of mathematical theories without the use of the iota-operator or the name-forming lambda-operator, whereas the latter require for their expression at least one of these non-standard term-operators. Furthermore, in hyper-slingshots PSLE is not used, whereas in conventional slingshots, PSLE plays a crucial inferential role. Hyper-slingshots implement simpler language tools in comparison with those used in conventional slingshots

The paper presents a formal model of the system of number representations as a multiplicity of mental number axes with a hierarchical structure. The hierarchy is determined by the mind as it acquires successive types of mental number axes generated by virtue of some algebraic mechanisms. Three types of algebraic structures, responsible for functioning these mechanisms, are distinguished: BASAN-structures, CASAN-structures and CAPPAN-structures. A foundational order holds between these structures. CAPPAN-structures are derivative from CASAN-structures which are extensions of BASAN-structures. The constructed formal model unifies two competitive conceptions of cognitive arithmetic: namely, the conception of the mental number line and the conception of parallel individuation. The paper is the continuation of a paper entitled Representational structures of arithmetical thinking, in which rich empirical evidence supporting the model is presented. The main result achieved in the present paper may be philosophically interpreted as an attempt to formalize the Kantian conception of the pure idea of time, understood as the a priori form of human arithmetical thinking. In this way, our theory may be comprehended as a result of applying the hard method of logical reconstruction of fundamental epistemological categories.

In the paper there is presented the argument for the situational paradigm of theory of language. In comparison to the nominativistic semantics it is argued in the paper that the propositional semantics is a better tool of explaining various speech acts in which the principle of compositionality is collapsed. In the paper there are also described referential mechanisms of metaphorical speech acts. In accordance with these mechanisms the metaphorical status of speech acts is determined by the collapse of Fregean referential compositionality of speech acts. In the paper there are constructed two notions of compositionality. First of them may be called classical Fregean concept of compositionality which establishes a semantic correlate of a complex speech act on a functional basis of semantic correlates of constituents of a complex speech act. According to the second notion of compositionality, correlates of constituents of a complex speech act are recursively deter-mined by a correlate of a complex speech act. Mataphorical speech acts possess such a property that correlates of their constituent expressions are determined in processes of de-coding by recursive compositionality functions. Maximal metaphors are speech acts in which recursive as well as Fregean compositionality collapse. In the paper it is argued that the traditional nominativistic semantics is not able to explain communicational functioning of metaphorical speech acts. That is why the conclusion of the paper resolves itself to the thesis that the situational semantic paradigm which should base on recursive notion of compositionality, is better than the nominativistic paradigm

The paper presents a new model of the structure of basic arithmetical representa-tions encoded in minds which enable them to solve simple story-tasks. According to the dominating paradigm the process of acquiring basic counting abilities culminates in encoding the exact number line in mind. This linear number representation enables the mind to solve simple story-tasks which do not require any mathematical mastery knowledge comprising laws, definitions and theorems. Some researchers try to show that the process of encoding the exact number line stems from transformations of the approximate number line (the mental number line) whereas others model this process as being dependent on the linguistic and logical resources of mind

The aim of the article is applying some version of phenomenological speech acts theory into the domain of philosophical (existential) discourse. There are identified various language-mechanisms of existential philosophising. Especially, locutionary (noematic) and illocutionary (noetic) aspects of acts existentialising are considered. The main thesis of the paper may be formulated in the following words: In acts of existential discourse, mechanisms of reference determine that an existentialising subject is directed to the mental entities such as illocutionary representations of fears, cares, wastes and other. The predication in such acts of philosophising is internal and also personal, temporal and sometime virtual. In the paper, there is also presented the illocutionary analysis of a fragment of Heidegger's text coming from Sein und Zeit