Thus the history of the human race is largely the record of a struggle for the means of subsistence caused by the pressure of population. Not that the population is necessarily dense. Some of the most thinly scattered peoples have had the greatest difficulty in making a living, simply because the available means of subsistence were exceptionally scanty, as the North American Indians, and above all in the continent of Australia before its settlement by Europeans. The study of human history shows that if the population was small, it was not owing to any defect in the natural powers of increase of human beings.

It will be seen that the Malthusian theory rests on two great facts: (1) on the physiological fact, viz. that all human beings are capable of indefinite increase; and (2) on a natural economic fact, that the means of subsistence are not capable of a corresponding indefinite increase, the ultimate reason of this being nothing else than the limited size of the planet on which we live. The inevitable result is the struggle for existence. The Darwinian theory of the struggle for existence has the widest application to human society and human history.

This struggle has gone on through a great variety of stages. In the earliest phases of human history it generally resulted in the extermination of the vanquished, and was often associated with cannibalism. As society advanced from the hunting and pastoral into the agricultural state, the victors saw that it would be their interest to spare the vanquished that they might enjoy the benefit of their labour as slaves. In this way began the institution of slavery, on which ancient civilisation rested. The warlike tribes that overturned the Roman Empire found that they could more easily and conveniently utilise the labour of the vanquished under the various forms of serfdom. In modern times free workers, destitute of capital, are ready under a system of competition to perform the labour of society for a wage that renders them the customary subsistence.

In the earliest stages the struggle was one for bare existence, not far removed above the lower animals; but as time went on, it began, as we have seen, to take a higher form. The main motive power, however, has always been the self-regarding principle in which the struggle originated. On the whole it was only a more rational and enlightened self-interest which dictated the change from extermination to slavery, from slavery to serfdom, and from serfdom to the system of competitive free labour. Idealism, the longing for a better life, has always had a considerable power in human affairs, and we hope that its influence will never cease to grow and prevail. Yet it could not be seriously maintained that the peoples who instituted slavery, serfdom, or the competitive system, were in the main actuated by ideal or high ethical motives. It is our duty to recognise with thankfulness that the inevitable progress of society has brought with it a higher life, even though it be merely due to a more enlightened self-interest.

Thus, while in its early stages it was a struggle for mere existence, in later times it has become more and more a struggle for a privileged or superior existence. The victors in most historic struggles have reserved to themselves the loftier functions of government, war and the chase, and the vanquished have been constrained to provide a subsistence both for their masters and themselves by means of labour. Life still is a struggle for the best places in society. And it is a particular object of struggle not to belong to the class of manual labour.

The competitive system is the latest form of the struggle for existence. It is not an accident, but the outcome of the prevalent historic forces. The time had come when free labour was found to be more efficient than servile labour. The feudal system, of which serfdom was a part, went down before the strongly centralised State. The competitive system is the form assumed by the struggle for existence in societies which were controlled by powerful central governments; it is industrial freedom under conditions of legality enforced by strongly constituted governments. In earlier and less settled states of society the struggle for existence used to be decided by more direct and forcible methods. In other days men slew their rivals; at the present time they undersell them.

And we need not say that the competitive system has been a process of selection, bringing to the front, as leaders of industry and also as heads of society, the fittest men.

The struggle for existence, therefore, has continued through human history, and does still continue. And we may feel assured that under the pressure of an ever-increasing population it will continue. The only question is regarding the form it is likely to take in the historic conditions which now tend to prevail all over the world.

For no conclusive solution of the population question is possible under any system. It has been a fundamental difficulty since the beginning of human society, and more than anything else may be regarded as the key to history. The migrations, wars, and conquests recorded in history have for the most part had their origin in want caused by the pressure of population on the extant means of subsistence. No doubt, ambition, vanity, suspicion, and restlessness have played a very considerable part of their own in the military annals of the race, but not nearly so large a part as is generally supposed. Historians have not given anything like adequate attention to the economic factors which have often so decisively operated in human affairs.

In its most comprehensive form, indeed, the population question does not concern the immediate future, for the world is not nearly replenished with human beings. In all the countries dominated by European civilisation, wealth has, owing to the vast mechanical development of the last hundred years, increased much more rapidly than population. But the question is one which does already practically concern the more populous centres over large areas of the world. In many of the old seats of population, both in Europe and the East, the struggle for existence is intense, and if not strongly counteracted, must tend to the increase of egotism, unscrupulousness, and general demoralisation. This is most observable in cases where a large population has to face the prospect of a declining prosperity. If the prosperity of this country were menaced by a great war, or a great shock to the national credit, or by both together, or simply by the slow decline of its industrial and commercial supremacy, the struggle for existence in our large towns would be unspeakable.