Papers

This paper concerns the categoricity problems, or Carnap’s problems, of some non-classical logics. I first review the categoricity theorems of LP and K3 proved by Tabakci (2024). I then point out a loophole in the proof of a proposition in the paper. I then turn to the categoricity of FDE, showing that FDE is categorical for the star models. I also prove that LP and K3 are not categorical for their star models

We can derive a paradox given structurism---roughly speaking, propositions are identical only if they have the same constituents in the same order. This thesis, together with basic set theory with ur-elements, in particular the existence of the set of all propositions (Set Plenitude), derives a contradiction provided that every formula expresses a proposition (Proposition Plenitude). It is proposed that a structurist could only resolve the paradox by rejecting the existence of the set of all Set Plenitude. However, I argue that they cannot resolve the paradox in this way due to the incoherence with their thesis. I also argue that structurism is incompatible with Proposition Plenitude.

Many hold that grounding and causation are alike: they are irreflexive, asymmetric and transitive; they are explanatory; they are necessitating, etc. This motivates grounding theorists to account for the similarity. One of the theories is a non-reductive counterfactual theory of grounding, along the interventionist lines. This theory uses structural equation models to formulate grounding and causation. In this paper, I argue against this approach to grounding by pointing out a loophole in the interventionist counterfactual theory of grounding: it will conflict with the usual logical laws. I also respond to several possible objections to my challenge.