The source of this divergence of view must be sought in the whole circumstances and character of the Greek states. Founded in the beginning by conquest, many of them still retained, in their internal structure, the marks of their violent origin. The citizens, for example, of Sparta and of Crete, were practically military garrisons, settled in the midst of a hostile population. These were extreme cases; and elsewhere, no doubt, the distinction between the conquerors and the conquered had disappeared. Still, it had sufficed to mould the conception and ideal of the citizen as a member of a privileged and superior class, whose whole energies were devoted to maintaining, by council and war, not only the prosperity, but the very existence of the state. The original citizen, moreover, would be an owner of land, which would be tilled for him by a subject class. Productive labour would be stamped, from the outset, with the stigma of inferiority; commerce would grow up, if at all, outside the limits of the landed aristocracy, and would have a struggle to win for itself any degree of social and political recognition. Such were the conditions that produced the Greek conception of the citizen. In some states, such as Sparta, they continued practically unchanged throughout the best period of Greek history; in others, such as Athens, they were modified by the growth of a commercial population, and where that was the case the conception of the citizen was modified too, and the whole polity assumed a democratic character. Yet never, as we have seen, even in the most democratic states, was the modern conception of equality admitted. For, in the first place, the institution of slavery persisted, to stamp the mass of producers as an inferior caste; and in the second place, trade, even in the states where it was most developed, hardly attained a preponderating influence. The ancient state was and remained primarily military. The great industrial questions which agitate modern states either did not exist at all in Greece, or assumed so simple a form that they did not rise to the surface of political life. [Footnote: There was, of course, the general opposition between rich and poor (see below). But not those infinitely complex relations which are the problems of modern statesmanship.] How curious it is, for example, from the modern point of view, to find Plato, a citizen of the most important trading centre of Greece, dismissing in the following brief sentence the whole commercial legislation of his ideal state: