Brett Reynolds

Homeostasis is a core biological concept concerning the way organisms maintain quantities within a given range. Mathematical models of homeostasis build on mechanisms for feedback control from engineering. The concept of control also figures centrally in causal analysis, where it is typically linked to interventions. This paper uses dynamic causal models (Iwasaki and Simon, 1994) to bridge these three domains, leading to the correction of a misunderstanding common in all of them. In each, control is regularly understood as aiming to maintain certain variables at constant values. Yet paradigm control feedback and homeostatic mechanisms do not maintain these variables constant, and intervening on them would destroy the mechanisms’ functions. Instead of focusing on how feedback loops allegedly maintain constancy, dynamic causal models reveal how control systems exploit such lower-scale feedback loops to produce higher-scale causal relationships. The discussion points toward a novel engineering-inspired approach to causal inference, and clarifies how biological and engineered systems combine existing mechanisms to perform increasingly complex functions.

Linguistic entities play a major part in almost all elements of our lives. Despite this, relatively little work exists in philosophy that considers what such entities are. In the work that does focus specifically on the metaphysics of words, the dominant view is type-realism, which posits that words are abstract types, instantiated by concrete tokens. This book argues, however, that type-realism faces a range of problems and that positing abstract types cannot help us to explain a range of ordinary everyday linguistic phenomena. In its place, this book argues in favour of a novel version of nominalism about words, holding that ordinary claims about words are in fact claims about collections of word-tokens only. Through combining nominalism with a trope-bundle metaphysics, this book proposes a 'bundle-nominalist' metaphysics of words, in which word-tokens are analysed as bundles of particular properties, which cluster in repeatable and predictable ways due to the acting of various homeostatic mechanisms. This view is then extended to other linguistic entities, such as morphemes, phonemes, sentences, and languages. The result is a unified metaphysics of linguistic entities, which is argued to be both consistent with linguistic theorising and highly explanatory. Words and Other Linguistic Entities outlines how this 'bundle-nominalist' metaphysics can provide new insights into a range of linguistic phenomena, including linguistic mistakes, linguistic change, and the nature of offensive language, and can help illuminate ongoing debates over the subject matter of linguistics and the evolution of language.