The Meaning of If

Despite its small stature, “if” occupies a central place both in everyday language and the philosophical lexicon. In allowing us to talk about hypothetical situations, “if” raises a host of thorny philosophical puzzles about language and logic. Addressing them requires tools from linguistics, logic, probability theory, and metaphysics. Justin Khoo uses these tools to navigate a maze of interconnected issues about conditionals, some of which include: the nature of linguistic communication, the relationship between logical and natural languages, and the relationship between different kinds of modality. According to Khoo’s theory, conditionals form a unified class of expressions which share a common semantic core that encodes inferential dispositions. Thus, rather than represent the world, conditionals are devices used to communicate how we are disposed to infer. Khoo shows that this theory can be extended to predict the probabilities of conditionals, as well as how different kinds of conditionals differ both semantically and pragmatically. Khoo’s book will make for a significant contribution to the literature on conditionals and should be of interest to philosophers, linguists, and computer scientists.