"Looking back over his pages, after nearly a quarter of a century more of investigation and experience, the author is grateful that he finds nothing to retract or expunge. He has but to add such thoughts and illustrations as have occurred to him in the course of his subsequent studies. He hopes that the supplementary chapters now published will be found more suggestive and mature than the preceding ones, while the same in aim and tone. For he still believes, as he did in his earlier time, that there is much of error and superstition, bigotry and cruelty, to be purged out of the prevailing theological creed and sentiment of Christendom. And he still hopes, as he did then, to contribute something of good influence in this direction. The large circulation of the work, the many letters of thanks for it received by the author from laymen and clergymen of different denominations, the numerous avowed and unavowed quotations from it in recent publications, all show that it has not been produced in vain, but has borne fruit in missionary service for reason, liberty, and charity."
