portant factor I can hardly mean to insist that it was the sole factor responsible for Roman decline and fall. For it is not credible that so rich and so complex a texture of life should depend upon any single factor.

Such would not be my assertion, nor is it my attempt. I have not undertaken to explain the complex fabric of Roman life; we are dealing here with the relatively simple problem of its disintegration. All that this study shows is that the progressive exhaustion of the soil was quite sufficient to doom Rome, as lack of oxygen in the air would doom the strongest living being. His moral or immoral character, his strength or his weakness, his genius or his mental defects, would not affect the circumstances of his death: he would have lived had he had oxygen; he died because he had none. But it must be remembered that while the presence of oxygen does not explain his life, the absence of it is sufficient to explain his death.

There is one other misunderstanding which I should like to guard against. So far as argumentation is concerned, this essay might be considered a continuation to the study published some time ago, dealing with the medieval village community.1 The reader will find there this statement:

Go to the ruins of ancient and rich civilizations in Asia Minor, northern Africa or elsewhere. Look at the unpeopled valleys, at the dead and buried cities, and you can decipher there the promise and the prophecy that the law of soil exhaustion held in store for all of us. It is but the story of an abandoned farm on a gigantic scale. Depleted of humus by constant cropping, land

1 Simkhovitch; "Hay and History." Political Science Quarterly, vol. xxviii, pp. 385-403, September, 1913.

could no longer reward labor and support life; so the people abandoned it. Deserted, it became a desert; the light soil was washed by the rain and blown around by shifting winds.1

I should hate to be responsible for a new fetish, an interpretation of historical life through exhaustion of soil. It is silly.

First of all deeply and gratefully is it felt that life with all its pain and its glory can be lived; word or brush may aspire toward its all too inadequate expression, but never will the scholar methodically and mechanically figure it out and interpret it.

But it is a mistake to think that social science is dealing with life. It is not. It deals with the background of life. It deals with common things, with what lives had in common, common conditions of existence, common purposes that these conditions suggest. They can and must be scientifically explained and determined, if social science is to be taken seriously. Scientific determination is accurate determination. What forces that circumscribe and govern our life must we unquestionably accept? Obviously, the physical forces. Under certain conditions we are born, we live and die. The limits of our mortal existence we cannot transgress. Nor can we change the heavenly course of suns and planets; we do not govern the seasons of the year; they regulate our life.

Within the laws of nature our lives begin and end. They limit and compass our existence.2 But the laws of nature without our active participation do neither

Simkhovitch, op. cit., p. 400.

"With apologies to Goethe's "Nach ewigen ehernen grossen Gesetzen müssen wir alle unseres Daseins Kreise vollenden."

feed nor clothe us. This active participation we call our work, our labor. Social labor varies in its productivity. At all times this productivity had and has its limits. These limits of the productivity of our labor become, for society, physical conditions of existence. Within these limits our entire social life must These limits life must accept as mandatory and implacable; to them it must adjust itself.

move.

The history of the productivity of our labor is the foundation of a scientific economic history, and the backbone of any and all history. Every law, every statute, every institution has obviously some purpose. But how are we to understand the purposes of the past unless we know the conditions which those purposes were to meet? The accurate knowledge of the productivity of our labor can explain to us why things were as they were, why they became what they are and what one may expect from the future.

In this study, however, which is not concerned with the details of Rome's life, one single, major and strikingly variable productivity factor suffices to solve the problem. That factor-the exhaustion of Roman soil and the devastation of Roman provinces-sheds enough light for us to behold the dread outlines of its doom.

one are intermixed with the holdings of his neighbors in the open fields. Let us examine such a village.

First of all, we find all the homesteads grouped together. In some localities they form one long street; in others, two streets; in still others, they are laid out in a semi-circle. Near the homesteads are the barns, stables, hovels, vegetable gardens and a few fruit trees, but never the field that belongs to the individual farmer.

The farming land presents a curious sight. It looks like a patchwork quilt. You see a number of land areas, of flats, of plots, as a rule square or oblong in shape, each of them divided into very numerous, narrow strips of land. Sometimes the three fields of the village form three quite uniform flats, subdivided into numerous strips, long and narrow, running in the same direction; but oftener you will find that each of the three fields is made up of many such flats, each of them subdivided into strips or ribbons of land. These strips belong to different owners, but they are not fenced. They are separated from each other by balks of turf, or unplowed land. Strips in some patches are, at times, so narrow that one wonders how they could be cultivated.

The individual peasant may own ten, twenty, or more strips in each of the three farming fields, but the strips of the individual farmer, even in the same field, do not adjoin each other. They are at times quite a distance apart. They are the farmer's individual property which he has inherited and which he may sell. But in the use of his property he is necessarily re