The eulogy of Locke in Voltaire's "Lettres Philosophiques" gave especial offense to the French churchmen. Voltaire writes to a friend that the censor might have been brought to give his approbation to all the letters but this one. "I confess," he adds, "that I do not understand this exception, but the theologians know more about it than I do, and I must take their word for it."[Footnote: Voltaire, li. 356 (_Letter to Thieriot,_ 24 Feb. 1733).] The letter to which the censor objected was principally taken up with the doctrine of the materiality of the soul. "Never," says Voltaire, "was there perhaps a wiser or a more methodical spirit, a more exact logician, than Locke." ... "Before him great philosophers had positively decided what is the soul of man; but as they knew nothing at all about it, it is very natural that they should all have been of different minds." And he adds in another part of the letter, "Men have long disputed on the nature and immortality of the soul. As to its immortality, that cannot be demonstrated, since people are still disputing about its nature; and since, surely, we must thoroughly know a created being to decide whether it is immortal or not. Human reason alone is so unable to demonstrate the immortality of the soul, that religion has been obliged to reveal it to us. The common good of all men demands that we should believe the soul to be immortal; faith commands it; no more is needed, and the matter is almost decided. It is not the same as to its nature; it matters little to religion of what substance is the soul, if only it be virtuous. It is a clock that has been given us to regulate, but the maker has not told us of what springs this clock is composed."[Footnote: Voltaire, xxxvii. 177, 182 (_Lettres philosophiques._ In the various editions of Voltaire's collected works published in the last century these letters do not appear as a series, but their contents is distributed among the miscellaneous articles, and those of the _Dictionnaire philosophique_. The reason for this was that the letters, having been judicially condemned, might have brought their publishers into trouble if they had appeared under their own title. Bengesco, ii. 9. Desnoiresterres, _Voltaire à Cirey_, 28, Voltaire, xxxvii. 113. In Beuchot's edition the letters appear in their original form).]