The consensus in contemporary philosophy is that health is a normative concept derived from social values, not a biological feature of organisms. We disagree. This project will produce a new and transformative account of health driven by our best current biology. The project addresses two Big Questions. First, what is an organism and what is the telos (goal) towards which an organism is structured? Theories of the organism have a long and distinguished history in philosophy, from Aristotle through Kant to early 20th century philosophy of biology and medicine. We argue that a philosophy of health must rest on a theory of the organism, which in turn should be based on the fundamental organising theory of the life sciences, the theory of evolution. Our second Big Question is whether there is a factual distinction between the Normal and the Pathological. Contrary to the current consensus we argue that describing the structure and function of a living organism necessarily draws distinctions between normal and pathological. Moreover, recent developments in biology provide biological reasons for changing our ideas about which phenotypes are healthy and which pathological. This is because new discoveries about the nature of organisms and their goals affect our theory of the organism. The presence of a philosophy of biology research group in one of Australia’s largest biomedical research institutes, The Charles Perkins Centre, and a set of existing collaborations with biological and biomedical researchers in the centre and around the world provides a unique opportunity to make philosophy an active participant in shaping innovative biomedical research. The philosophical work will suggest novel approaches to specific biomedical questions and we will conduct collaborative proof-of-principle projects with our biomedical colleagues to demonstrate the value of the new approach to health.