So far, I have ventured the conclusion that our good as living beings lies in our coherently maintaining ourselves in a healthily functional condition as what we, in our whole being, are. What is good for us, we might fairly though broadly say, is to live a healthy life. But what is health? Like life itself, health is a familiar thing that we nevertheless find difficult to define. Generally, it is far more difficult to determine that a being is healthy, or that it is not, than it is to determine whether it is alive, so we are all the more in need of a workable characterization of health. It would be lovely if we could find some definition that was clear, simple, unambiguous, precise, and accurate. Such definitions are to be found in mathematics, but the living world tends to be not as neat as that. Health, like life, is a matter of ambiguity and imprecision, and it is a matter of more and less. In such matters as this, the simplest answers often tend not to be the most correct. What it is to be healthy is also determined in some part by the environment in which the living being occurs, as well as by the condition of that being itself. The nature of health is more a matter of factual discovery (and sometimes of choice of priorities) than it is of theoretical definition. My endeavor here is to develop a conception of health that is workable and adequate for our purposes. As Aristotle correctly observed,

I would extend that (I believe in the spirit of Aristotle) to note that we must look for the sort of precision and accuracy appropriate to a given subject matter. Life is to be understood, if at all, only in its own terms. Nonetheless – indeed, all the more so – there are important matters about life and health to be considered, and we should not use Aristotle's disclaimer as an excuse for vaguing out.