Have devout men, during the three thousand years which history chronicles, been under a delusion in believing that "there is a spirit in man, and the Almighty giveth him understanding"? Is popular Christianity "wide of the truth, and a disfigurement of the truth," as an eminent writer the other day asserted? Such questions float in our literature and find their way into our homes and our sanctuaries. Although no importance is to be attached to the reckless assertion that the outworks of Evangelical Religion are in danger, and that the very citadel itself is not impregnable, it is undoubtedly true that its modern adversaries--reputable and otherwise--are bold, active, and skilful, and there is need that its defenders should be alert and vigilant. It will not do to rely altogether on the defensive lines and tactics of our predecessors. Each generation has the stronghold entrusted to its care, and new appliances are, from time to time, required to resist novel as well as resuscitated modes of assault. However certain be the ultimate triumph of His cause whose right it is to reign, the rate of its progress depends upon the faithfulness and heroism of His servants at their various posts of labour and conflict. To change the figure. The mirror which reflects Divine truth has to be preserved and kept bright by human instrumentality. Superstition, in the murky atmosphere of sacerdotalism, clouds it; by false philosophy it is liable to be dimmed; while crude science or unsound criticism, removing the silver lining to make the glass more transparent, makes it useless. He does well who is able to act as its conservator, and in some measure cleanse the surface, that obscurity may be removed and eternal truth discerned. I am aware that, as a rule, it is not desirable that hostile literature should be helped into notoriety, and that believers should be troubled with exploded fallacies and disturbed by arguments against the truth as it is in Jesus a hundred times answered. As Robert Hall justly remarks:--"It is degrading to the dignity of a revelation, established through a succession of ages by indubitable proofs, to be adverting every moment to the hypothesis of its being an imposture, and to be inviting every ignorant sophist to wrangle about the title, when we should be cultivating the possession." But there are exceptions to every rule, and as I am not addressing a promiscuous audience, but the members of a society whose rule is to discuss all subjects without limitation, I venture to think I am justified in bringing under your notice a recent heterodox book which is so well written as to be likely to mislead if it be not neutralized. And the more so, if I can make the author not only answer himself, but other writers whose anti-Christian arguments are not put forth anonymously, but with the authority of well-known names and much reputation in the world of letters and science.