The first part of this essay develops the idea of logic as the science of thought, articulating, and thus being, the self-consciousness of thought. It explains that logic, so understood, is nothing other than metaphysics, the science of what is in so far as it is. Self-consciousness, then, thought itself, is not empty, but the source of all content. The second part of the essay discusses the opening paragraphs of Hegel’sScience of Logic; it shows how, in these paragraphs, thought is (...) revealed to be the source of its own content in virtue of its original negativity. Thus the second part begins to make concrete the idea of logic provided by the first. (shrink)

European Journal of Philosophy, Volume 29, Issue 4, Page 988-1009, December 2021.

Contrary to the contemporary view that negation is a logical operation that modifies the mere content of a thought or judgment, but not the act of thinking or judging it, Kant maintains that negation is an act of logical apperception through which I exclude a thought or judgment from what ‘I think.’ In this paper, I argue against two interpretations of Kant’s account of logical negation. According to the first, negation is a subjective psychological act of excluding an erroneous judgment. (...) Against this, I will show that for Kant, negation is an operation of logical, not empirical apperception. The second interpretation views logical negation as an objective representation either of a relation of opposition or of non-being. I argue that, on the contrary, the logical function of negation is merely formal, not material, and therefore does not have semantic content. The paper’s final section develops a positive conception of logical negation as a formal function of judging. (shrink)

In bilateral logic formulas are signed by + and –, indicating the speech acts assertion and denial. I argue that making an assumption is also speech act. Speech acts cannot be embedded within other speech acts. Hence we cannot make sense of the notion of making an assumption in bilateral logic. Attempts to solve this problem are considered and rejected.

Frege is an anti-psychologist about logic who takes logic to be sharply distinguished from psychology. However, Frege also takes judgment, which seems to be a subject of psychology, to be essential to logic. Van der Schaar attempts to explain away this tension by arguing that judgments relevant to logic in Frege are not mental actions psychology deals with. Against this reading, I show that for Frege, judgments are mental actions consistently. The tension in question should be explained away by clarifying (...) the sense in which judgment is essential to logic for Frege. He takes judgment to be essential to logic because he thinks that logic requires judgments to be performed. Logic requires logicians to be committed to truth, and it is by judgments that we are committed to truth. If Frege takes judgment to be essential to logic only in this sense, he is not thereby committed to logical psychologism. (shrink)

Criticizing psychologism about logic in the Foreword of Grundgesetze, Frege examines an answer to the question of how we can justify our acknowledgment of logical axioms as true—the logical laws that cannot be proved from other laws. The answer he entertains states that we cannot reject logical axioms if we do not want to give up our judgment altogether. Suspending his judgment about this answer, Frege points out that it is still compatible with his anti-psychologist conception of logic. There are (...) two issues with this paragraph. First, it is difficult to read this paragraph consistently. Second, it is not clear why Frege brings up this particular view regarding the justification for logical axioms in the middle of his criticism of psychologism. This paper develops a consistent interpretation of this paragraph. The view on the justification for logical axioms, which Frege is dealing with, is neo-Kantian. In the paragraph, Frege is criticizing a psychologistic misunderstanding of the neo-Kantian justification for logical axioms. The way Frege explains away this misunderstanding shows that he takes the neo-Kantian justification for logical axioms to be a non-evidential epistemic warrant if it is an epistemic warrant. It is this notion of non-evidential epistemic warrant that Frege suspends his judgment about. Thus, the paragraph shows that Frege has a reason to have reservations about neo-Kantianism. Furthermore, it turns out that the sole issue between Frege and psychological logicians is whether truth is objective, which provides a different way to explain away a much-discussed tension between Begriffsschrift and Frege's anti-psychologism. (shrink)

ABSTRACT Frege characterizes judgement as the acknowledgement of the truth of a thought, appearing thereby to rule out false judgement. First in this paper I explain Frege’s characterization so that it does not have this consequence. Frege is not saying that for a subject S to judge that p is for S to acknowledge the truth of the thought that p. Rather, he is articulating judgement’s nature within self-consciousness. From within, to judge means to acknowledge a truth. Second, I suggest (...) that this articulation is centrally operative in Frege’s argument for the indefinability of truth. As Frege argues, it follows from judgement’s self-consciousness that truth is indefinable. (shrink)

What makes certain definitions fruitful? And how can definitions play an explanatory role? The purpose of this paper is to examine these questions via an investigation of Frege’s treatment of definitions. Specifically, I pursue this issue via an examination of Frege’s views about the scientific unification of logic and arithmetic. In my view, what interpreters have failed to appreciate is that logicism is a project of unification, not reduction. For Frege, unification involves two separate steps: (1) an account of the (...) content expressed by arithmetical claims and (2) the justification of that content. The distinction between these steps allows us to see that there are two notions of definition at play in Frege’s logicist work, viz., one concerned with conceptual analysis, the other concerned with the construction of gap-free proof. I then use this discussion to explain how Frege employs his definitions to defend an epistemological thesis about arithmetic, and to clarify Grundlagen’s fruitfulness condition of definitions, and thereby address two interpretive puzzles from the recent literature. (shrink)

In Die Grundgesetze der Arithmetik (I, §48), Frege introduces his rule of the fusion of horizontals, according to which if an occurrence of the horizontal stroke is followed by another occurrence of the same stroke, either in isolation or “contained” in a propositional connective, the two occurrences can be fused with each other. However, the role of this rule, and of the horizontal sign more generally, is controversial; Michael Dummett notoriously claimed, for instance, that the horizontal is “wholly superfluous” in (...) Frege's logical system. In this paper, we challenge Dummett's view by providing a comprehensive analysis of the significance of the horizontal stroke. After some preliminary remarks, we argue that even if Frege's connectives in some sense “contain” the horizontal, yet they are total functions. Then, we take up the question of the sense expressed by the horizontal, and we claim that, unlike other sentential operators, the horizontal is not sense‐compositional. Finally, we consider the semantic and pragmatic aspects of Frege's horizontal in connection to his judgment stroke and the double judgment stroke. Contra Dummett, we argue that the horizontal is a special and indispensable element of Frege's logic. (shrink)