Now a government of this type is always in want of money. The spiritual Roman Empire was as costly an institution as the court and the bureaucracy of Diocletian and his successors. The same necessity which suppressed democracy in the Church drove it to elaborate an oppressive system of taxation, in which every weakness of human nature was systematically exploited for gain, and every morsel of divine grace placed on a tariff. But this method of raising revenue is only possible while the priests can persuade the people that they really control a treasury of grace, from which they can make or withhold grants at their pleasure. It stands or falls with a non-ethical and magical view of the divine economy which is hardly compatible with a high level of culture or morality. The Catholic Church has thus been obliged, for purely fiscal reasons, to discourage secular education, particularly of a scientific kind, and to keep the people, so far as possible, in the mental and moral condition most favourable to such transactions as the purchase of indulgences and the payment of various insurances against hell and purgatory. Another necessity of absolute government is the repression of free criticism directed against itself. Heresy and schism in an autocratic Church take the place of treason against the sovereign. Cyprian, in the third century, had already laid down the principles by which alone the central authority could be maintained. 'Ab arbore frange ramum; fractus germinare non poterit. A fonte praecide rivum; praecisus arescit.... Quisquis ab ecclesia separatus adulterae iungitur, a promissis ecclesiae separatur. Alienus est, hostis est. Habere non potest Deum patrem, qui ecclesiam non habet matrem.' Schismatics are therefore rebels, whose lives are forfeit under the laws of treason. Heretics are in no better case; for the Church is the only infallible interpreter both of Scripture and of tradition; and to differ from her teaching is as disloyal as to secede from her jurisdiction. Even Augustine could say, 'I should not believe the Gospel, if the authority of the Church did not determine me to do so'; a statement which a modern ultra-montane has capped by saying, 'Without the authority of the Pope, I should not place the Bible higher than the Koran.' Bellarmine claims an absolute monopoly of inspiration for the Roman Church on the ground that Rome alone has preserved the apostolic succession beyond dispute.[52] As for the treatment which heretics deserve, the same authority is very explicit.