Chapter Three of Life, Liberty and the Pursuit of Utility discusses the role of health in philosophical discussions of the good life.
Throughout most of the history of thought, philosophers have underplayed the importance of physical health as a constituent of happiness. Aristotle, for example, appears to have believed that the enjoyment of health throughout life depended greatly on one’s exercise of virtue and avoidance of vice—in other words, on the goods of the soul. But we can only deduce his position on the role of health in the good life by looking at his opinion regarding intentional suffering. Aristotle suggests that a man cannot be happy under torture. However, a person may be racked with pain through disease no less than through the malevolence of a tyrant, so that in consistency Aristotle should agree that a modicum of good health is a necessary condition for the good life.
As with Aristotle, most philosophers prior to the Industrial Revolution were more concerned with the possibility of human life being threatened by other human beings than by disease. Locke and Hobbes provide two examples of the centrality of such concerns. But as the period of modern economic growth picked up, so did concern with the impact of progress on levels of health and violence. Thomas Carlyle maintained that the pursuit of utility by capitalists, instead of bringing great happiness to great numbers, had enriched the few by reducing the masses to a condition resembling Hobbes’s original state of nature. ‘Our life is not a mutual helpfulness’ he wrote ‘but rather, cloaked under due laws of war, named ‘fair competition’ and so forth, it is mutual hostility.’ Similarly, and acutely aware of how ill their poorer contemporaries were faring in newly industrialised societies, both Mill and Marx gave a prominent place to welfare in the centre of their notion of happiness.