It is well known that the propositional modal logic GL of provability satisfies the de Jongh-Sambin fixed-point property. On the other hand, Montagna showed that the predicate modal system QGL, which is the natural variant of GL, loses the fixed-point property. In this paper, we discuss some versions of the fixed-point property for predicate modal logics. First, we prove that several extensions of QGL including NQGL do not have the fixed-point property. Secondly, we prove the fixed-point theorem for the logic QK + ▢n+1 ⊥. As a consequence, we obtain that the class FH of Kripke frames which are transitive and finite height satisfies the fixed-point property locally. We also show the failure of the Craig interpolation property for NQGL.Finally, we give a sufficient condition for formulas to have a fixed-point in QGL.
In “From Alethic Anti-realism to Alethic Realism” Künne distinguishes between alethic realism and alethic anti-realism. This article examines whether or not alethic anti-realism is appropriate, when we take the position of using commonsense to settle a philosophical problem. To that end, I will first review Künne's theory. Next, I will point out that Putnam's natural realists are alethic realists, that Wright's moderate internalists are alethic ani-realists, and that Wright argues against Putnam. Then, I will argue that Künne's conception of truth escapes the criticism of Wright's argument. Lastly I will also review Tennant's argument for anti-realism, and argue that in spite of Tennant's argument, alethic anti-realism is not appropriate when considered from a commonsense point of view.
Intention-based semantics (IBS) serves as the paradigm in the field of speaker meaning analysis. However, it has grappled with a well-known problem: the infinite regress of a speaker's intentions. Theorists such as Grice, Schiffer, Davis, and Green have tried to remedy the situation; however, no one has found any solutions until now. The present paper claims that the inability of IBS theorists to resolve the regress problem may be attributed to the conflict between two basic assumptions that they espouse: representationalism and the transparency of speaker meaning. When both are adopted alongside each other, as the current paper shows, the regress problem immediately emerges. It follows, then, that it would be prudent to reject IBS to sufficiently analyze speaker meaning.
Monism is a metaphysical view according to which there is only one fundamental object. This paper will explore monism within the context of truthmaker theory, or Truthmaker Monism, a view rarely discussed in literature. Although few truthmaker theorists defend monism, at least explicitly, some theories seem to share the spirit of monism to some extent. Interestingly, they are proposed as solutions for the same problem, called the problem of negative truth. A close examination will show that while each of these solutions can account for the problem, they are unsatisfactory for different reasons. This paper will suggest a novel solution to the problem of negative truth which preserves the advantages of existing solutions while avoiding the difficulties with which they are faced.
Existence monism (EM) is a metaphysical view asserting the existence of only one concrete object. EM is well known for its radicalness, and encounters difficulty in terms of its prima facie inconsistency with truisms. This paper aims to propose an alternative (and somewhat easy) way to overcome this difficulty and indicate another means by which the possibility of EM can be defended. I will present a package of theses that are intended to be combined with EM, which I call Linguistic Ontology with the One as Semantic Glue (LOOSG). I will show that this package (in combination with EM) provides a systematic explanation as to why truisms hold while only one concrete object actually exists. In other words, I will argue that if an existence monist embraces LOOSG, the desired explanation for truisms is then available to her. In addition, it will also be noted that LOOSG has a theoretical virtue, in that it only presupposes the framework of standard semantics. Based on these discussions, I offer LOOSG as a viable option for existence monism.
This paper seeks to reveal a formal similarity between Jonathan Schaffer's argument for monism and Benedict de Spinoza's argument for substance monism. Since Spinoza was referred to as a “priority monist” in Schaffer (2010), some scholars have discussed the validity of this interpretation. Among these, Mogens Lærke's criticism is the most important and critical. According to his criticism, Spinoza is not even a “monist” because substance cannot be counted as one. In this paper, I argue that the “tiling constraint,” which Schaffer introduces for inquiring what the basic actual concrete objects are, does not depend on counting, pace Lærke. Schaffer invokes it to give directions to monism. Furthermore, I show that the indivisibility of substance is Spinoza's counterpart of one of two conditions which constitute the tiling constraint. He argues that the substance cannot be divided into substantial parts. In conclusion, Spinoza's position is allowed to be at least formally considered as a monism in Schaffer's sense.