These are the circumstances which explain the rude and vigorous scepticism of Diderot's first performances. And they explain the influence of Shaftesbury over him. Neither Diderot nor his contemporaries were ready at once to plunge into the broader and firmer negation to which they afterwards committed themselves. No doubt some of the politeness which he shows to Christianity, both in the notes to his translation of Shaftesbury, and in his own Philosophic Thoughts, is no more than an ironical deference to established prejudices. The notes to the Essay on Merit and Virtue show that Diderot, like all the other French revolters against established prejudice, had been deeply influenced by the shrewd-witted Montaigne. But the ardour of the disciple pressed objections home with a trenchancy that is very unlike the sage distillations of the master. It was from Shaftesbury, however, that he borrowed common sense as a philosophic principle. Shaftesbury had indirectly drawn it from Locke, and through Hutcheson it became the source and sponsor of the Scottish philosophy of that century. This was a weapon exactly adapted for dealing with a theology that was discredited in the eyes of all cool observers by the hysterical extravagances of one set of religionists, and the factious pretensions of their rivals. And no other weapon was at hand. The historic or critical method of investigation was impossible, for the age did not possess the requisite learning. The indirect attack from the side of physical science was equally impossible. The bearing of Newton's great discovery on the current conceptions of the Creator and the supposed system of the divine government, was not yet fully realised. The other scientific ideas which have since made the old hypothesis less credible, were not at that time even conceived.