The attempts at change, indeed, were many. Conspiracies were chronic; and when one failed the conspirators were blinded according to Byzantine rule: emperors on the other hand were often unmade; but the political machinery remained the same. In the period to Heraclius, the ruling class at Constantinople were mainly of Roman stock; under the Iconoclastic emperors, who were Asiatics, it was mainly Asiatic; later it became substantially Greek, as each party drove out the other; but all alike maintained the old imperial ideals. "Men of every rank," says the historian Finlay, "were confined within a restricted circle, and compelled to act in one unvarying manner. Within the imperial palace the incessant ceremonial was regarded as the highest branch of human knowledge.... Among the people at large, though the curial system of castes had been broken down, still the trader was fettered to his corporation, and often to his quarter or street ... amidst men of the same profession.... No learning, no talent, and no virtue could conduct either to distinction or wealth, unless exercised according to the fixed formulas that governed the State and the Church. Hence even the merchant, who travelled over all Asia, and who supported the system by the immense duties that he furnished to the government, supplied no new ideas to society, and perhaps passed through life without acquiring any." Yet such is the strength of the biological force of variation that even in religion there was chronic heresy. We have seen, in tracing the history of western belief in the eleventh and twelfth centuries, how a strenuous anti-clerical heresy, the Paulician, had arisen and thriven in the East, defying the bloodiest persecution, and developing in the old fashion into a force of hostility to the empire. After that heresy had been thus fatally expelled, others arose. In the twelfth century, under the theological emperor Manuel Comnenus, there was a return to the inexhaustible problem of the incarnation: men disputed as to how God could at the same time be a sacrifice and the offerer thereof; and the emperor himself, convicted of heresy, came round to the orthodox view, whatever it was. Soon the dispute took a new form, over the awkward text "My Father is greater than I"; and the emperor gave an orthodox decision which he engraved on tables of stone for the great Church, denouncing death on all who taught otherwise. As usual, the dispute was not settled, and the later emperor Andronicus was fain to take down the tablets and forbid all discussion on the subject. All the while anti-clerical and anti-ceremonial heresy persisted; and the burning alive of the monk Basil, founder of the Gnostic Bogomiles, did not mend matters. The brutal sack and pillage of Constantinople by the Latin crusaders, and the generation of western tyranny that followed, did much to unify the Greek people of the thirteenth century in a common hatred of their masters, whom they at length cast out;