'Biological functions are much discussed but little understood. Justin Garson appeals to the explanatory depth of functional explanations to develop a powerful general theory of functions. This book will serve as a reference point for future debate.' David Papineau, King's College London

'Garson does a superb job of explaining just how central a philosophical understanding of functions is to a wide array of discussions in philosophy and science. These discussions include how to count junk DNA in the ENCODE project, how to classify traits and individuate mechanisms, how different kinds and levels of biological explanations relate to each other, the nature of health and disease, the nature of mental disorder, and even the fundamental basis of thought itself. In addition to being an excellent introduction to these issues, this book gives us a fresh, lively and comprehensive presentation of Garson's distinctive contributions.' Karen Neander, Duke University, North Carolina

'[In] What Biological Functions Are and Why They Matter, Justin Garson formulates the major philosophical issues that a relevant theory of function should solve as three main puzzles, namely (1) the function/accident distinction, (2) dysfunction, and (3) the etiological explanatory value of function.' Etienne Roux, Metascience