Review of Biological Autonomy Jason Winning and William Bechtel* Alvaro Moreno and Matteo Mossio, Biological Autonomy. Dordrecht: Springer (2015), 221 pp., $129.00. In Biological Autonomy , philosophers Alvaro Moreno and Matteo Mos- sio present a new theoretical framework for understanding how living or- ganisms differ from other physical systems. Their framework, which they call the “autonomous perspective,” addresses biological organisms qua systems. They show how it generates insights into a wide range of questions in philosophy of biology such as, Does causation operate top down? What are functions? Which is more fundamental for the origin of life—metabo- lism or replication? What distinguishes cognition as a kind of biological pro- cess? Moreno and Mossio’ s systems-oriented approach, with its holistic focus on the organizational features of biological systems (including the entire spectrum from bacteria to large multicellular organisms), is a welcome and refreshing departure from the contemporary plethora of mechanistic ap- proaches that emphasize reductive accounts of biological systems as decom- posable into hierarchies of parts and operations. The autonomous perspective also provides insights into why mechanistic explanation must be supple- mented with other explanatory approaches. In this review, we briefly sketch some of the core ideas of the framework and how the authors apply it to two central problems in philosophy of biology: the nature of functions in biology and how to understand cognition in biological systems in general. Constraints and Closure. In this section, we explain two core concepts that Moreno and Mossio employ: the concept of a constraint in a biological system and the concept of organizational closure. Moreno and Mossio’ s theory is inspired to a large extent by Francisco Varela and Humberto Received January 2016. *To contact the authors, please write to: William Bechtel, Department of Philosophy, University of California, San Diego; e-mail: wbechtel@ucsd.edu. Philosophy of Science, 83 (July 2016) pp. 446–452. 0031-8248/2016/8303-0008$10.00 Copyright 2016 by the Philosophy of Science Association. All rights reserved. 446 All use subject to University of Chicago Press Terms and Conditions (http://www.journals.uchicago.edu/t-and-c).