What Is Disease?

Biological science does not try to distinguish betweeln health and disease. Biology is concerned with the interaction between living organisms and their environment. What we call health or disease is quite irrelevant. These reactions between the individual and his environment are complex. The individual and his surroundings form an integrated system which we can arbitrarily divide into two parts. There is an "external" component, by which we mean such factors as light, heat, percentage of oxygen in the air, quantity of minerals or vitamins in food, micro-organisms in food or air, and so on. These can induce changes in what we arbitrarily call the "internal" component. Here we include such crude factors as anatomical structures, or finer details like composition of intercellular fluid, or secretions of glands, or changes of electrical potential in nerve or muscle. Medical science studies the reactions of the iinternal component and its relations with the external component. A separation is artificial, but none the less necessary for convenience and practicality. In any investigation science exerts its prerogative to break down the total complex event into simple parts. The scientist focuses his attentions on limited sequences, and partial aspects. If he tries to preserve the unity entire, he would remain hopelessly bogged down. For example, if we ask, what happens to the food that we eat?, we are asking a question too complex for an intelligible answer. To make any reply meaningful, we must analyze the problem into simpler parts. We must specify what happens where. In the mouth? In the stomach? In the small intestines? Or in the liver, the pancreas, or the blood stream? We must specify what food. Fats? Carbohydrates? Proteins? And in what quantity? Starvation diets, average amounts, or surfeits? And then of course, when? At what points in the time-scale? At what age, at what temporal relation to exercise, or stress? All of these questions reflect our fundamental interest, of trying to isolate the relevant conditions that attend the phenomenon. But there are so many relevant aspects; what is relevant for one person might nlot be significant for another. If everyone had the same sort of liver or the same sort of pancreas, investigation would be a lot simpler. But they don't. Some individuals, for example, have stones in their gall bladders. Others have very small amounts of thyroid gland secretion. Still others harbor amoebae in their intestinal tract. In reply to our question, what happens to the food that we eat?, our answer will depend, in part, on whether the individual has stones in the gall bladder or amoebae in his colon. Clearly, this "total environment" of which we speak is not identical for all people. Science tries to isolate as many discrete factors as possible. Some will apply to virtually all humans without exception, others may concern only a minute fraction of the total population. Science, in studying reactions within the total environment, cares not a whit about "health."