The Commitment Theory of Convention: A Critical Assessment by Professor Mahmoud Morvarid

One of the pivotal issues in contemporary philosophy of language is the nature of linguistic meaning: what is it in virtue of which a word or a phrase has a specific linguistic meaning it actually does? A foundational theory of meaning aims to provide a systematic answer to this question. Although this question has not been explicitly raised in Shiite uṣūl al-fiqh, the uṣūlīs have long been concerned with a related problem, namely, the nature of convention (waḍʿ), and have proposed several theories in this regard. It seems that by “waḍʿ,” the uṣūlīs mean (at least implicitly) the process or condition that bestows words and phrases with their meanings. Thus, from the uṣūlīs’ theories of convention, we can infer their foundational theories of meaning, even if these theories are not explicitly formulated in uṣūl texts. One prominent uṣūlī theory of convention is the commitment (taʿahhud) theory, proposed by Nahāvandī (d. 1322), Ḥā’irī (d. 1355), Isfihānī (d. 1362), and most notably Khūʾī (d. 1413), among others. Given the close connection between the notions of convention and linguistic meaning in uṣūl al-fiqh, we can construct a foundational theory of meaning from the commitment theory of convention. At first approximation, such a theory of meaning runs as follows: Commitment Theory of Meaning: S means M in a group G if and only if the members of G are committed that whenever they intend to induce M (or induce a particular attitude relevant to M) in their audience, they utter S. This formulation is a schematic statement; depending on whether S is a word, a declarative sentence, or a non-declarative sentence, the parenthetic phrase (namely, “induce a particular attitude relevant to M”) will take a more specific form. The commitment theory of meaning is particularly interesting as it closely aligns with the basic idea of use theories of meaning, especially the intention-based theory of meaning developed by Paul Grice. In this paper, I will provide a detailed comparison between the commitment theory of meaning and the Gricean theory of meaning. I will then argue that although the commitment theory of meaning represents a significant step towards a sophisticated theory of meaning in uṣūl al-fiqh, it suffers from important problems in its accounts of both word meaning and sentence meaning. As we shall see, the Gricean theory of meaning fares better regarding at least some of these criticisms. Finally, I will tentatively propose that the notion of commitment might be employed in the context of William Alston’s theory of meaning (another form of the use theory of meaning) to shed light on the nature of illocutionary rules.