tions. 1 The result is an important one from the point of view of method.

In biology, excepting in the case of individual adaptation of artificial selection, direct observation -the historical method, if we may so call it—is not available for the study of the origin and modification of organisms. Phylogeny, the science of organic kinship, resorts to other methods, and particularly to the comparative method in its various forms

(a) Morphology, the science of determining the phylogeny of organs by comparing them with the organs of other creatures belonging to the same systematic group.

(b) Palæontology, which determines the direct ancestors of living creatures.

(c) Embryology, which, so far as it is founded upon the principle of recapitulation, investigates the development of organs in the individual, and draws conclusions therefrom bearing upon its descent.

1 Among animals there is a special factor which gives a stability to the specific characters not found elsewhere-this is reproduction. Specific characters being common to the whole line of descent, are very deeply enrooted in the organism. They are not easily modified by the influence of new environments, but maintain their likeness to one another in spite of external conditions. They are regulated by an internal force, notwithstanding the importunities to variation offered from outside. This force is heredity, and heredity accounts for the precise way in which specific characters may be defined. In society this internal force is wanting. (Les Règles de la méthode sociologique. Durckheim, Paris, F. Alcan, 1895.)

(d) Teratology, which compares normal with abnormal forms for the same purpose.

In sociology these various systems of comparison are only of a secondary value, owing to the great variability of social forms, while the historical method of investigation assumes a greater importance. In sociology, however, there are methods. analogous to the comparative methods of biology:

(a) Archæology corresponds to paleontology.

(b) Social morphology, by comparison of series of institutions, makes up to a certain extent for the absence of direct observation of their origin and development. Thus, to Thus, to use the phrase of Bagehot, by studying the customs and institutions of modern savages, the prehistoric living may be made to throw light upon the prehistoric dead. If an institution be found in full operation among savages, of which a vestige still exists among more civilized people, it may be assumed that the vestige was at some time fully functional among the latter. It must be borne in mind, however, that in many instances such vestiges are the result of imitation. Theodore Reinach has shown that this applies in the case of circumcision.1

This gravely weakens the conclusions drawn by Spencer from the survival of this custom among

1 De quelques faits relatifs à l'histoire de la circoncision chez les peuples de la Syrie (Th. Reinach, L'Anthropologie, 1893, vol. iv., pp. 28 and following).

certain Australian tribes. Granting, he says, that circumcision, the removal of teeth, and other similar mutilations imply a condition of political or religious subjection—or both-no longer existing among these tribes, the custom is obviously the vestige of a more complex social condition. This conclusion seems the less reliable, since, according to the Rev. J. Matthew, the rite of circumcision was probably introduced into Australia by natives of Sumatra, and this view is confirmed by the local distribution of the custom and by other evidences of the same origin, such as the paintings which have been discovered in certain caves.1

(c) Teratology and social embryology also play a part in sociology, but it is of less importance than the others.

Certain customs among criminals show a resemblance to the habits of primitive man. On the other hand, we find cases where the individual development of an institution or society is a mere repetition of the development through which similar institutions and societies of other epochs and places have passed. Thus, for instance, there still exists in some parts of modern Russia a voluntary agricultural commune, for the periodical division of the land, an institution which existed more universally in the sixteenth and seventeenth centuries during

1 The Cave Paintings of Australia (Journal of the Anthropological Institute of Great Britain and Ireland, April 1893, pp. 51 and following).

the existence and after the disappearance of family communities.1

In studying the development of these new communities, one can, in a measure, picture to oneself the development of laws of property, which were current in other countries at other times, and of which we possess little or no direct information. It is, however, hardly necessary to insist upon the hypothetical quality of such conclusions.

Our methods show, then, that organisms and societies exhibit considerable differences as well as analogies, a necessary result of their different natures. These few remarks must suffice; to add to them, we should have to overstep the limits we have set to this treatise, enter into well-worn controversies, and anticipate our own conclusions. Having merely explained our terminology, and indicated our general views, we will proceed to the subject of our investigations.

1 Tableau des origines et de l'évolution de la propriété et de la famille, p. 170 (Kowalevsky).

BOOK I

UNIVERSALITY OF DEGENERATIVE

EVOLUTION

PART I

DEGENERATION IN THE DEVELOPMENT OF INSTITUTIONS AND ORGANS

THE term "Evolution" does not in itself convey an idea of either progress or degeneration. It comprises all the changes undergone by an organism or society independently of the question as to whether these changes are favourable or otherwise. The evolution of an organ, or of the different parts of an organ, is degenerative if it tends to the ultimate decay of that organ or of its parts, and the facts are shewn by means of arranging series of fossils or living forms, and comparing them. Evolution is progressive if it tends to the development of an organ or to the formation of a new organ.

These definitions may be applied mutatis mutandis-to the changes undergone by societies and institutions or their constituent parts.

The ideas of progress and of degeneration seem at first sight to relate to diametrically opposite phenomena. The term "progressive evolution "