Moreover, the Church appeared to them to be, and was, in fact, the most open and the worst defended side of all the vast edifice which they were assailing. Her strength had declined at the same time that the temporal power of the Crown had increased. After having been first the superior of the temporal powers, then their equal, she had come down to be their client; and a sort of reciprocity had been established between them. The temporal powers lent the Church their material force, whilst the Church lent them her moral authority; they caused the Church to be obeyed, the Church caused them to be respected--a dangerous interchange of obligations in times of approaching revolution, and always disadvantageous to a power founded not upon constraint but upon faith. Although the Kings of France still called themselves the eldest sons of the Church, they fulfilled their obligations towards her most negligently: they evinced far less ardour in her protection than in the defence of their own government. They did not, it is true, permit any direct attack upon her, but they suffered her to be transfixed from a distance by a thousand shafts. The sort of semi-constraint which was at that time imposed upon the enemies of the Church, instead of diminishing their power, augmented it. There are times when the restraint imposed on literature succeeds in arresting the progress of opinions; there are others when it accelerates their course: but a species of control similar to that then exercised over the press, has invariably augmented its power a hundredfold. Authors were persecuted enough to excite compassion--not enough to inspire them with terror. They suffered from that kind of annoyance which irritates to opposition, not from the heavy yoke which crushes. The prosecutions directed against them, which were almost always dilatory, noisy, and vain, appeared less calculated to prevent their writing than to excite them to the task. A complete liberty of the press would have been less prejudicial to the Church. ‘You consider our intolerance more favourable to the progress of the mind than your unlimited liberty,’ wrote Diderot to David Hume in 1768. ‘D’Holbach, Helvetius, Morelet, and Suard, are not of your opinion.’ Yet it was the Scotchman who was right; he possessed the experience of the free country in which he lived. Diderot looked upon the matter as a literary man--Hume, as a politician.