PREFACE

For many years the phraseology of evolution has been current. Scientists use it because evolution has come to be the underlying idea of several modern sciences; and less serious writers find their vocabularies colored by what has now become a popular doctrine. Evolution is the fashion, and to affect evolutionary terminology is one method of lending a pseudodignity to the trivial. All this is peculiarly marked in writings having to do with sociological subjects.

Naturally the terms originally used by Darwin and his followers have suffered, in passing from hand to hand, a considerable amount of damage. Like coins that have been circulating indiscriminately, they have lost their sharpness of outline and definiteness of superscription. It is almost impossible to discover what some authors who deal with social topics - let alone the host of popular writers and orators-mean by evolution.

In the endeavor, some years ago, to dispel from my mind the vagueness of the evolution

ary terminology which had settled there as the result of reading along sociological lines, I went back to Darwin and Huxley-to the mint, as it were and tried to get their conceptions before me. This was a most useful enterprise, and its results have been incorporated in my thinking and teaching ever since. I have come to believe that any fruitful study of the science of society must rest upon a clear understanding, even though it be but a layman's, of the Darwinian theory.

Then came the question as to the validity of extending Darwinism and its terminology to the life of human society. As to this matter, I have come to believe that the Darwinian factors of variation, selection, transmission, and adaptation are active in the life of societies as in that of organisms. Selection, for example, is none the less selection- not merely like natural selection in a vague way-because it is observed in another field and is seen there to act after another mode characteristic of that field.1 And I have tried to get at the nature of these evolutionary factors as displayed in their societal mode. The outcome of this study takes form in a simple, and in 1 Cf. pp. 14-16 below.

many ways obvious arrangement of well-known facts; but because the results reached have been of use to me and to my students, in getting and keeping our bearings for the study of the science of society, I publish them, at length, in the hope that some others may derive such advantage from them.

The working out of this line has resulted in an extension upon the conception of the folkways, as developed by my predecessor, Professor Sumner. This conception has always seemed to me to be the link connecting organic and societal evolution, and the extension of which I speak consists in good part in bringing out that point of view, to which Sumner himself gave no special attention.1 Regarding this essay, as I do, as an extension of Sumner's work, I have taken my quotations, so far as I could, from his writings.

When it came to putting what follows into book form, the choice was presented between accompanying the argument with numbers of cases in illustration, as one does in college lectures, or of securing brevity and compactness by reducing illustration to a minimum. The latter alternative was chosen because, as it

1 See Note at end of this volume.