Is Common Sense Enough

Science and Common Sense. By John Langdon Davies. (Hamish Hamilton, Ltd. 10s. 6d.) TuE purpose of this book is excellent ; it is to make clear the relation of science to common sense, and thus to help those who are not specialists in science out of the perplexity in which the paradoxes of modern science necessarily place them. Mr. Langdon Davies begins by pointing out that what any age regards as common sense grows out of a con-

ception of the world belonging to an earlier age. Science is therefore continually at war with common sense, which is driven to fight a perpetual rearguard action. With this

view of the relation of science and common sense no one would disagree. Yet we are so trained to cling to common-sense views and to the attitudes founded on them that the case against common sense cannot be too often restated.

But Mr. Langdon Davies takes us far beyond the discussion of this particular problem. In the second part of the book he goes on to explain that there are not only rigid common- sense beliefs about the world of observation, but also equally rigid common-sense beliefs about the moral world, which lay down what man " ought to do." These are also founded on a conception of the world and of man, which has long since been superseded by the progress of science :

" It is clear that the brute facts of orthodox morality are derived themselv6s from science, that is, from man's picture of the universe, and, moreover, that they are derived from an obsolete and exploded science. . . . If the scientists of those days (two thousand years ago) had not thought as they did about the universe, the moral theologian would never have constructed his particular world of make-believe ; so that the moral theologian to-day who tries to force on us his selection of brute facts is trying to force on us the science of antiquity."

This latter discussion, which takes up almost half of the book, is concerned almost exclusively with sexual morality. Sexual morality is notoriously loaded with pre-scientific taboos ; but much as it may stand in need of reform, it is a pity that Mr. Langdon Davies should have so much

restricted his discussion to this, with the exclusion of all other moral problems.

But excellent as is the purpose of the book it has serious shortcomings, which make it- unlikely to prove -of much help to those who want to learn to think clearly on the problem of the relationship between common sense and scientific knowledge, or who want to recognize clearly the

way in which morality can be satisfactorily reconceived in the light of present knowledge. The book itself is a plea for careful scientific thought, and yet Mr. Langdon Davies is reckless in his use of a profusion of terms which he does

not distinguish from one another, either by any attempt at definition, or by any consistency in use. For example, he uses the expression " brute fact " almost as synonymous with " reality," with " unknowable," with " the ultimate X from which things are composed " and with " something which can be simply defined." This is particularly confusing ; as the

expression " brute fact " is adopted from Professor White- head's Science and the Modern World, in which it is used

with a quite clear but totally ,different meaning, to describe experimental observations which contradict and overthrow conceptions current at the time. Much of the book is devoted to the distinction which the author makes between scientific reality (" brute fact," &c.) and make-believe. We are told :

"the world (of reality) is, by definition, everything in the universe which is Completely independent of the feelings, wishes, subjective reactions of the human being, and all these have been invented, added to the world of reality, by mankind for its own purpose. . . . A star is a thing in the world of reality ; a beautiful star is a thing in the world of Make-believe. A physical sexual reaction is a thing in the world of reality ; love is a thing in the world of make- believe. Gravitation is the name we give to something observed in the world of reality ; God is the name we give to something we feel in the world of make-believe."

In view of these bold distinctions, we cannot but wonder how Mr. Langdon Davies would classify a toothache, or even the perception of a scientist observing the fibre of an electro- meter through a microscope. The distinction which Mr. Langdon Davies no doubt had in mind is that between that part of experience which can be expressed in terms of propositions about which the universal agreement necessary to science can be obtained, and that part of experience which cannot be reduced to a least common denominator in this way. But such a statement of the problem as this is not once suggested in the whole book.

The task of writing about science and common sense is ultimately a philosophical one, which must begin with the clear understanding of what is meant by " science " and what by " common sense." It is, of course, highly desirable that popular accounts of such important philosophical problems should be written ; but a thorough under- standing of the philosophical problem of science and common sense is necessary for a satisfactory popular account of it to be written. It is here that Mr. Langdon Davies fails us.

The book does not make difficult reading, as an abundance of witty remarks carry one lightly through its pages. For most readers its chief interest will be in the convincingly sincere protest which it makes against orthodox morality, about wide] there is such general and growing dissatisfaction. At the same

time it shows how great are the difficulties which lie in the way

of discovering a satisfactory basis for a new morality. J. 1'.