After introducing semantic anti-realism and the paradox of knowability, the paper offers a reconstruction of the anti-realist argument from understanding. The proposed reconstruction validates an unrestricted principle to the effect that truth requires the existence of a certain kind of “demonstration”. The paper shows that that principle fails to imply the problematic instances of the original unrestricted feasible-knowability principle but that the overall view underlying the new principle still has unrestricted epistemic consequences. Appealing precisely to the paradox of knowability, the (...) paper also argues, against the BHK semantics, for the non- constructive character of the demonstrations envisaged by semantic anti-realism, and contends that, in such setting, one of the most natural arguments for a broadly intuitionist revision of classical logic loses all its force.Tras presentar el anti-realismo semántico y la paradoja de la cognoscibilidad, el artículo ofrece una reconstrucción del argumento anti-realista basado en la comprensión. La reconstrucción que se propone valida un principio irrestricto, del que se sigue que la verdad requiere la existencia de un determinado tipo de “demostración”. El artículo muestra que este principio no implica las instancias problemáticas del original principio irrestricto de la cognoscibilidad realizable, y que la concepción general que subyace al nuevo principio todavía tiene consecuencias epistémicas irrestrictas. Apelando precisamente a la paradoja de la cognoscibilidad, el artículo argumenta además, en contra de la semántica BHK, a favor del carácter no constructivo de las demostraciones que contempla el anti-realismo semántico, y defiende que, en ese marco, uno de los argumentos más naturales a favor de una revisión a grandes rasgos intuicionista de la lógica clásica pierde toda su fuerza. (shrink)

In other works, I’ve proposed a solution to the semantic paradoxes which, at the technical level, basically relies on failure of contraction. I’ve also suggested that, at the philosophical level, contraction fails because of the instability of certain states of affairs. In this paper, I try to make good on that suggestion.

Milne [2005] argued that a sentence saying of itself that it does not have a truthmaker is true but does not have a truthmaker. López de Sa and Zardini [2006] worried that, by parity of reasoning, one should conclude that a sentence saying of itself that it is not both true and short is true but not short. Recently, Milne [2013] and Gołosz [2015] have replied to López de Sa and Zardini’s worry, arguing in different ways that the worry is (...) illfounded. In this paper, I’ll address these replies and argue that they fail to dispel López de Sa and Zardini’s worry, bringing out in the process some broader points concerning the use of self-referential sentences in arguments in philosophy of logic. (shrink)

It is argued that there are sentences and pairs of sentences, belonging to the family of ‘truth-tellers’ and ‘no–no sentences’, such that it is possible to prove (and, hence come to know) their truth-value. It is, therefore, concluded that the kind of pathological feature affecting some truth-tellers and no–no sentences is not due to the specific kind of circularity characterizing their truth-conditions and must, thus, depend on some other reason.