to move or not to move the arm would be uncaused and unaffected by antecedents, when you have just provided so strong an antecedent as the desire to save a thousand pistoles. It was, perhaps, well enough for Voltaire to content himself with vague poetical material for his poetical discourse on Liberty, but from Diderot, whether as editor or as writer, something better might have been expected than a clumsy reproduction of the reasoning by which men like Turretini had turned philosophy into the corrupted handmaid of theology. The most extraordinary thing about this extraordinary article still remains to be told. It was written, we may suppose, between 1757 and 1762, or about that time. In June, 1756, Diderot wrote to a certain Landois, a fellow-worker on the Encyclopaedia, a letter containing the most emphatic possible repudiation of the whole doctrine of Liberty. "Liberty is a word void of sense; there are not and there never can have been free beings; we are only what fits in with the general order, with organisation, with education, and with the chain of events. We can no more conceive a being acting without a motive than we can conceive one of the arms of a balance acting without a weight; and the motive is always exterior and foreign to us, attached either by nature or by some cause or other that is not ourselves. _There is only one sort of causes, properly speaking, and those are, physical causes._"[188] And so forth in the vein of hard and remorseless necessarianism, which we shall find presently in the pages of the System of Nature.[189] There is only one explanation of this flagrant contradiction. Diderot must have written on Liberty just as he wrote on Jesus Christ or the Bible. He cannot have said what he thought, but only what the persons in authority required him to pretend to think. We may he sure that a letter to an intimate would be more likely to contain his real opinion than an article published in the Encyclopaedia. That such mystifications are odious, are shameful, are almost too degrading a price to pay for the gains of such a work, we may all readily enough admit. All that we can do is to note so flagrant a case, as a striking example of the common artifices of the time. One other point we may note. The fervour and dexterity with which Diderot made what he knew to be the worse appear the better cause, make a still more striking example of his astonishing dramatic power of throwing himself, as dialectician, casuist, sophist, into a false and illusive part.