The spirit of inquiry, which always leads men to question the authority of these customs and moral codes and of their religious sanctions and thus tends to weaken them, is, then, a socially disruptive force, at the same time that it is the source of all progress. Hence, though the free play of the intellect and of the spirit of inquiry may secure for a time the rapid progress of civilisation, it cannot alone secure continued progress. Continued progress has only resulted where there has been maintained a happy balance between the conservative and the progressive forces, between the authority of custom and the moral code on the one hand and the free activity of the intellect on the other. Wherever the progressive force has outrun the conservative, progress has been first rapid and then has come abruptly to an end. Greece exemplified this process in the clearest manner. It was the excessive seeking of individuals for their own power and glory, unrestrained by the customs and religious systems which their intellect had outgrown, that ruptured the bonds of society, plunged the State into war and civil strife, and eventually destroyed it by the extermination of the Greek aristocracy. The same is true of the brilliant but brief periods of rapid progress exhibited by the medieval Italian States. Intellect outran and undermined morals, and progress was brought to an end.

Some observers have maintained that history will pass the same verdict upon modern France, and that most of our leading nations of the present day are seriously threatened by the same danger.

Any long continued progressive evolution of the mind of a people has been, then, a rare exception in the history of the world; partly because the free play of the spirit of inquiry and of the intellectual faculties, which is the source of all progress, exerts a socially disruptive tendency, so that progress is by its very nature dangerous to the stability of any nation; but partly also because the free play of the spirit of inquiry has been so rarely achieved or permitted, so that even such progress as has led on to social disruption has been exceptional.

A long period of intellectual and moral stagnation in the rigid bonds of custom and religion has been the rule for nearly all the peoples of the earth, so soon as they had attained to a settled mode of existence. The primary question, then, to be answered in seeking to account for the progress of nations, is—What conditions enabled the spirit of inquiry to break the bonds of custom and religion and to extend man’s knowledge of man and of the world in which he lives?

Bagehot, in considering more particularly the progress of political institutions, put the problem in much the same way. He pointed out that the first age of the life of nations is always an age dominated by custom resting on unquestioned religious sanctions; an age in which there is often a vast amount of discussion of detail, as, for example, discussion of the details of military expeditions, but never discussion of principles; and he maintained that an age marked by the discussion of principles, involving the questioning of traditions, moral and intellectual, initiates and characterises every period of progress.

There is much to be said for the view that the most important condition of progress in its earlier stages was in most cases, perhaps in all, the conquest of a more primitive people by one more advanced in culture or of superior racial type, who remained to settle in the conquered territory, and, not driving out or exterminating the conquered inhabitants, established themselves as a governing class. History and archaeology show that this occurred at least once in most of the areas where nations have developed spontaneously to any considerable degree; the earliest known instances being those of Egypt and Chaldea as long as ten thousand years ago. The same thing occurred again in India, and later still in Greece; and throughout early European history the process was frequently repeated in various areas. Every one of the modern peoples of Europe has been formed through such fusion by conquest of two peoples, in some instances several times repeated; and, though none of these modern European peoples originated their own civilisations, but largely took over by imitation the civilisation ready made for them by the more precocious peoples of Asia and by Greece and Rome, these fusions and the resultant composite character of the European peoples no doubt have tended greatly to promote progress. And it is easy to see how in several ways such a fusion by conquest of two peoples must have tended to set free the spirit of inquiry, that prime condition of progress. Three of these seem to have been of chief importance.

The most obvious way in which progress has been promoted was that the conquering invaders became a leisured aristocracy, having their material needs supplied by the labour of the indigenous population, which became a more or less servile class. All the ancient civilisations were thus founded upon servile labour. We may be sure that, until such a social system resulted from conquest, no people made much progress; because all individuals were fully occupied in securing their means of subsistence, either by warfare, by the tending of herds, or by agriculture. Each people was self-supporting, and knew no or few needs beyond those which their own labour was able to supply; and labour was individual, or was co-operative only among small groups, such as the communal family groups. It could, therefore, undertake no great works, whether of building or engineering, such as large public buildings, irrigation, or road making. Each family consumed what it produced, and consequently there was no large accumulation of capital; for there were no motives for storing up their primitive wealth, and generally no wealth of durable and storable form.

But, as soon as a ruling class could dispose of the labour of a large part of the population, making them work for a mere subsistence wage, there was initiated that régime of capital and labour on which, up to the present time, all civilisation has been founded. Wealth was accumulated; great works, such as the pyramids, demanding enormous expenditure of human life and work, could be undertaken; and a leisured class was created, which, being freed from the necessity of bodily toil, was able to turn its energy to speculative inquiry, to the enjoyment of art and luxury, to directing and organising the labour of the multitude, to inventing the tools that render labour more effective, to studying natural phenomena such as the cycle of the seasons, a more accurate knowledge of which added to the productivity of labour; for it was in the service of wealth production, that in the main science arose, especially mathematics and mechanical and astronomical science, arithmetic and geometry through the need of a practical art of measurement, astronomical science through the need of foreseeing the seasons.