Minor Insight from a Major Figure


The Limits of Science, by Peter Medawar New York: Harper & Row, 108 pages, $11.95

Do you know what an obiter dictum is? It is an incidental remark or aside from a grand personage, usually a judge. Unfortunately, this slight book, rather than exploring the profound subject of its title, is no more than an obiter dictum from a—to be sure—highly and rightly honored scientist, Sir Peter Medawar. (Among many other awards, he holds a Nobel Prize in recognition of his work in immunogenetics.) In view of the feebleness of this book's reach—and this is truly surprising, given both the inherent interest of the topic and the author's frequently professed admiration for and familiarity with the writings of the philosopher Sir Karl Popper—I cannot recommend that you spend time on it.

The question treated by Medawar is, of course, not new. And it should be of interest to us, since we are so accustomed to taking for granted that any problem is at least potentially resolvable by means of the methods of science (assuming this methodology were sufficiently advanced). Given this predisposition, it would surely be news if classes of problems turned up to which the scientific method is inherently inapplicable.

Well, such classes of problems have turned up, and so we might have expected Medawar to give us an introductory tour d'horizon of the general topic. Certainly, one of the puzzling oddities of the 20th century is the discovery that there are inherent limits to the precision with which the fundamental particles making up matter can be located in space. Rather than occupying discrete sites, their position can only be described as a "cloud of probability," with the particle having a significant chance at any single instant of being anywhere within the cloud.

The discovery of this deep-level uncertainty has rippled through other areas of intellectual endeavor (especially philosophy). For this reason, then, a discussion of this type of limit on what science can discover and its implications for everyday life would be of high interest to the nonspecialist reader. Does Medawar discuss it? Not at all.

Alternatively, we might have hoped that he would address the limits to scientific inquiry examined by Sir Karl Popper in The Poverty of Historicism and by Friedrich Hayek in The Counter-Revolution of Science (the former arguing the inapplicability of scientific methods—prediction, in particular—to the study of history and the latter finding related flaws in many efforts to apply scientific methodology to the other social sciences). Both of these books are written in dense and sometimes nearly impenetrable prose. A translation of the important ideas contained in them into nonscholarly language would be a meritorious service. (Medawar prides himself, with justice, on being a graceful writer of great civility.) But again, this topic is not touched.

With what sorts of limits to science does Medawar, then, deal in this book? There are only three questions that he specifically cites as being intrinsically beyond science, all having to do with what he calls first and last things. These three questions are weighty, and I hope you are all sitting solidly in your seats as you read the words I am about to reveal:

1. How did everything begin?
2. What are we all here for?
3. What is the point of living?

Sort of dazzles you, doesn't it? And just what deep principle is it that renders these questions inherently beyond the capability of science to answer? Why, the Law of Conservation of Information (hereafter, the Law). And what is that? Simply the proposition that no purely logical process can increase the information content of the axioms and premises or observation statements from which it proceeds. The Law just described makes it clear that from observation statements or descriptive laws having only empirical furniture (such as propositions of science), there is no process of reasoning by which we may derive theorems having to do with first and last things, such as the three questions just listed.

But we do not have to challenge the overall validity of the Law to recognize that there is a presumption smuggled in here that Medawar nowhere makes explicit, namely, that clues to first and last things are not already inherent in the empirical furniture of science. If they are, then the bound placed on science's ability to give meaningful answers to questions about first and last things by the Law vanishes.

The other two questions seem unsuited to a scientific or objective answer for a much simpler reason than their violating the Law. They inherently involve individual tastes, and hence it would be about as meaningful to try to give an objective answer to, for example, the question, What is the point of living? as it would be to the question (which is at the root of Marx's notion of surplus value and capitalist exploitation of labor), What is the value of an hour of labor?

How does Medawar recommend that we try to get answers about such first and last things, if not through science? Why, through myth, metaphysics, imaginative literature, and religion. And how, having given up science, can one hope to arrive at true answers to these ultimate questions, and what authority, if not objective truth, can be cited to resolve disputes about these matters?

According to Medawar, it is not useful or even meaningful to ask whether they are true or false. Instead, what matters is only whether the answers bring peace of mind. In short, he is saying that the answers to the ultimate questions are whatever anyone wants them to be, and there is no way to distinguish true answers from false ones, nor even to rank the possible answers according to a criterion of truth. We need not have waited for the appearance of this book to gain this minor insight.

William Havender is a free-lance writer with a background in science.