Frege: Judgment Stroke

It is often claimed that the theory of function levels proposed by Frege in Grundgesetze der Arithmetik anticipates the hierarchy of types that underlies Church’s simple theory of types. This claim roughly states that Frege presupposes a type of functions in the sense of simple type theory in the expository language of Grundgesetze. However, this view makes it hard to accommodate function names of two arguments and view functions as incomplete entities. I propose and defend an alternative interpretation of first-level (...) function names in Grundgesetze into simple type-theoretic open terms rather than into closed terms of a function type. This interpretation offers a still unhistorical but more faithful type-theoretic approximation of Frege’s theory of levels and can be naturally extended to accommodate second-level functions. It is made possible by two key observations that Frege’s Roman markers behave essentially like open terms and that Frege lacks a clear criterion for distinguishing between Roman markers and function names. (shrink)

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)

I develop a new reading of Frege’s argument for the indefinability of truth. I concentrate on what Frege literally says in the passage that contains the argument. This literal reading of the passage establishes that the indefinability argument is an arguably sound argument to the following conclusion: provided that the Fregean conception of judgment—which has recently been countered by Hanks—is correct and that truth is a property of truth-bearers, a vicious infinite regress is produced. Given this vicious regress, Frege chooses (...) to reject that truth is a property of truth-bearers. Frege’s choice leads to a unique version of the Fregean conception of judgment. His unique conception of judgment can cope with Hanks’s recent criticisms against the Fregean conception. (shrink)

Gottlob Frege takes logic to be the science of truth throughout his career. However, the mature Frege makes remarks which seem to go against the idea that logic is the science of truth. This paper shows that we can explain away this tension in the mature Frege’s conception of logic if we accept that truth is an object, that is, the truth-vale True qua the reference of a sentence, for Frege. Even though the main thesis of this paper is a (...) conditional, I provide reasons why we ought to consider the possibility seriously that truth is an object for Frege. I also explain how we can make sense of Frege’s conception of logic as the science of truth while accepting truth is an object. (shrink)

I investigate the role of the subject in judgment in Kant, Frege, and Husserl, situating it in the broader and less-often-considered context of their accounts of presentation as well as judgment. Contemporary philosophical usage of “representation” tends to elide the question of what Kant called the constitution of content, because of a reluctance, traced to Frege’s anti-psychologism, to attend to subjectivity. But for Kant and Husserl, anti-psychologism allows for synthesis as the subjective act necessary for both “mere presentation” and judgment. (...) In Begriffshrift, Frege alludes to a significant logical role for the subjective act of judgment, and in later work, traces of this logical role remain in the intensional notions of grasping a thought and judging as acknowledging its truth. But Frege’s anti-psychologism blocks interpreting these subjective notions in term of synthesis. Although similar in certain ways to Frege and equally anti-psychologistic, Husserl’s theory of judgment in the Logical Investigations maintains a role for subjective syntheses for presentations and judgments, and goes beyond Kant in allowing for a kind of objectivity at the level of non-judgment presentations. These two great anti-psychologists at the dawn of the parallel heydays of linguistic and phenomenological analysis are thus differentiated by the fates they assign to the act of synthesis. (shrink)

Frege’s use of a judgment stroke in his conceptual notation has been a matter of controversy, at least since Wittgenstein rejected it as “logically quite meaningless” in the Tractatus. Recent defenders of Frege include Tyler Burge, Nicolas Smith and Wolfgang Künne, whereas critics include William Taschek and Edward Kanterian. Against the background of these defenses and criticisms, the present paper argues that Frege faces a dilemma the two horns of which are related to his early and later conceptions of asserted (...) content respectively. On the one hand, if content is thought of as something that has propositional structure, then the judgment stroke is superfluous. On the other hand, if what is to the right of the judgment stroke is conceived as a sort of name designating a truth-value, then there is no consistent way to avoid construing the judgment stroke as a kind of predicate, and thereby fail to do justice to the act-character of judgment and assertion. (shrink)

Assertion plays a crucial dual role in Frege's conception of logic, a formal and a transcendental one. A recurrent complaint is that Frege's inclusion of the judgement-stroke in the Begriffsschrift is either in tension with his anti-psychologism or wholly superfluous. Assertion, the objection goes, is at best of merely psychological significance. In this paper, I defend Frege against the objection by giving reasons for recognising the central logical significance of assertion in both its formal and its transcendental role.

Frege's philosophy of language includes detailed views on judgments. His formal logic - the Begriffsschrift - documents some of these views in the introduction and treatment of the judgment stroke. In current logic such an expression is either entirely ignored or, appearing as turnstile, plays an fundamentally different role. In this paper I put forward four claims: (i) Considering Frege's Begriffsschrift, it is methodologically palpable why the judgment stroke was omitted in nearly all logical systems developed after Frege. (ii) The (...) Frege-style inclusion of the judgment stroke in a formal language represents a partial implementation of results from speech act theory. (iii) A more comprehensive implementation, not limited to the judgment stroke, helps to satisfy justified expectations about formal languages and logical calculi. (iv) Such an implementation has not yet been achieved in the current logical mainstream. (shrink)

Frege believes that the real power to determine the sentence to show the logic of interest to "true." And with the word "truth" of redundancy on the same, he believes the lack of everyday language and the ability to determine the appropriate symbol. However, Frege, it seems that he invented the concept of text assigned to a special force to determine the sign: determine the bar. This paper attempts to demonstrate, although Frege until the final stage of his academic career (...) to determine the bar still insist to retain its logic into the language system, but the concepts and words in this design does not meet him on the relationship between logic and fuzzy real insight. A key step in the argument, we will by means of Husserl on the "faith of variation" to clarify the doctrine of "judge" and "determined" by Frege between the neglected difference. On this basis, we finally prompted a brief on the logic of Frege and true insight into the relationship between the interpretation of ambiguous direction. (shrink)

One of the most striking differences between Frege's Begriffsschrift (logical system) and standard contemporary systems of logic is the inclusion in the former of the judgement stroke: a symbol which marks those propositions which are being asserted , that is, which are being used to express judgements . There has been considerable controversy regarding both the exact purpose of the judgement stroke, and whether a system of logic should include such a symbol. This paper explains the intended role of the (...) judgement stroke in a way that renders it readily comprehensible why Frege insisted that this symbol was an essential part of his logical system. The key point here is that Frege viewed logic as the study of inference relations amongst acts of judgement , rather than – as in the typical contemporary view – of consequence relations amongst certain objects (propositions or well-formed formulae). The paper also explains why Frege's use of the judgement stroke is not in conflict with his avowed anti-psychologism, and why Wittgenstein's criticism of the judgement stroke as 'logically quite meaningless' is unfounded. The key point here is that while the judgement stroke has no content , its use in logic and mathematics is subject to a very stringent norm of assertion. (shrink)

The syntax of Frege's scientific language is commonly taken to be characterized by two oddities: the representation of the intended illocutionary role of sentences by a special sign, the judgement-stroke, and the treatment of sentences as a species of singular terms. In this paper, an alternative view is defended. The main theses are: the syntax of Frege's scientific language aims at an explication of the logical form of judgements; the judgement-stroke is, therefore, a truth-operator, not a pragmatic operator; in Frege's (...) first system, '⊦ Δ' expresses that the circumstance Δ is a fact, and in his second system that the truth-value - Δ is the True; in both systems, the judgement-stroke is construed as a sign sui generis, not as a genuine predicate; its counterpart in natural language is the syntactic "form of assertoric sentences", not the truth-predicate; neither in Frege's first nor in his second system sentences are treated as singular terms. (shrink)

This paper brings to light a new puzzle for Frege interpretation, and offers a solution to that puzzle. The puzzle concerns Frege’s judgement-stroke (‘|’), and consists in a tension between three of Frege’s claims. First, Frege vehemently maintains that psychological considerations should have no place in logic. Second, Frege regards the judgementstroke—and the associated dissociation of assertoric force from content, of the act of judgement from the subject matter about which judgement is made—as a crucial part of his logic. Third, (...) Frege holds that judging is an inner mental process, and that the distinction marked by the judgement-stroke, between entertaining a thought and judging that it is true, is a psychological distinction. I argue that what initially looks like confusion here on Frege’s part appears quite reasonable when we remind ourselves of the differences between Frege’s conception of logic and our own. (shrink)

The purpose of the article is to explain two curious doctrines maintained by frege and rejected by wittgenstein in the 'tractatus logico-philosophicus'. that a special assertion sign is necessary was maintained by frege because he wanted to apply his concept-writing to ordinary language, and it was rejected by wittgenstein because his concern in the 'tractatus' was with scientific assertions only. frege's paradoxical notion that 'the concept horse is not a concept' was a consequence of his symbolizing functions by 'unsaturated' expressions. (...) wittgenstein's picture theory eliminated expressions for relations and thereby avoided the fregean paradox. (shrink)