Volume 12 (2020): Edition 58 (December 2020)
SPECIAL ISSUE: ON THE VERY IDEA OF LOGICAL FORM

This introduction is a short critical presentation of the topic and main arguments of Andrea Iacona’s book Logical Form. Furthermore, it summarizes the commentators’ views on two central issues: Iacona’s rejection of the uniqueness thesis, i.e. his claim that no single notion of logical form can be adequate to the tasks that logical form has been supposed to perform, and the relation between a sentence’s logical form and its truth conditions.

I discuss Andrea Iacona’s idea that logical form mirrors truth conditions, and that logical form, and thus truth conditions, are in turn represented by means of adequate formalization. I criticize this idea, noting that the notion of adequate formalization is highly indefinite, while the pre-theoretic idea of logical form is often much more definite. I also criticize Iacona’s claim that certain distinct sentences, with the same truth conditions and differing only by co-referential names, must be formalized by the same formula (in the same context). I criticize this claim, noting that it imposes implausible demands on adequate formalization. Finally, I offer some brief remarks on the connection between Iacona’s ideas and the distinction between logical and non-logical constants.

The paper reviews some conceptions of logical form in the light of Andrea Iacona’s book Logical Form. I distinguish the following: logical form as schematization of natural language, provided by, for example, Aristotle’s syllogistic; the relevance to logical form of formal languages like those used by Frege and Russell to express and prove mathematical theorems; Russell’s mid-period conception of logical form as the structural cement binding propositions; the conceptions of logical form discussed by Iacona; and logical form regarded as an empirical hypothesis about the psychology of language processing, as in the Discourse Representation Theory tradition. Whereas neither schematization, nor the use of special languages for mathematics, raise general methodological or empirical difficulties, other conceptions of logical form raise at least apparent problems.

In a recent book, Logical Form: between Logic and Natural Language, Andrea Iacona argues that semantic form and logical form are distinct. The semantic form of a sentence is something that (together with the meanings of its parts) determines what it means; the logical from of a sentence is something that (all by itself) determines whether it is a logical truth. Semantic form does not depend on context but logical form does: for example, whether ‘This is this’ is a logical truth depends on whether the two occurrences of ‘this’ are used to demonstrate the same individual. I respond by claiming that logical form is indifferent to reference and is sensitive only to obligatory co-reference. When the speaker intends both occurrences of ‘this’ to be interpreted the same way the logical from of ‘This is this’ is a=a, while in a context where the speaker has no such intention it is a=b. This proposal allows a much more conservative revision of the traditional picture than the one suggested by Iacona. Instead of identifying the logical form of a natural language sentence by seeking a formalization in an artificial language, we obtain it through abstraction from its syntactic analysis: replacing the non-logical expressions by schematic letters, making sure that we use identical ones if and only if the speaker intended co-reference.

In the core chapters 4–6, Iacona (2018) argues against the “Uniqueness Thesis” (UT), stating that “there is a unique notion of logical form that fulfils both the logical role and the semantic role” (39), where the former “concerns the formal explanation of logical properties and logical relations, such as validity or contradiction” (37), and the latter “concerns the formulation of a compositional theory of meaning” (ibid.). He argues for this on the basis of relations of coreference among referential expressions, names and indexicals. From what I take to be a fundamental agreement on most relevant issues, here I will nonetheless press him to clarify the notions of intrinsicness and the logical and semantic role of logical form on which he relies.

In his new book, Logical Form, Andrea Iacona distinguishes between two different roles that have been ascribed to the notion of logical form: the logical role and the semantic role. These two roles entail a bifurcation of the notion of logical form. Both notions of logical form, according to Iacona, are descriptive, having to do with different features of natural language sentences. I agree that the notion of logical form bifurcates, but not that the logical role is merely descriptive. In this paper, I focus on formalization, a process by which logical form, on its logical role, is attributed to natural language sentences. According to some, formalization is a form of explication, and it involves normative, pragmatic, as well as creative aspects. I present a view by which formalization involves explicit commitments on behalf of a reasoner or an interpreter, which serve the normative grounds for the evaluation of a given text. In previous work, I proposed the framework of semantic constraints for the explication of logical consequence. Here, I extend the framework to include formalization constraints. The various constraints then serve the role of commitments. I discuss specific issues raised by Iacona concerning univocality, co-reference and equivocation, and I show how our views on these matters diverge as a result of our different starting assumptions.

In this paper I provide five separate responses, one for each of the contributed papers, in order to clarify some crucial aspects of the view defended in my book.