Every book should have a purpose. Notwithstanding the popular character of much that is contained in these pages, the purpose of this volume is a serious one.

I acquired the belief in the habitability of other worlds when quite young, and it long ago grew into a settled conviction.

Firmly held by this idea, what is called the astronomical difficulty in theology gave me great concern. When I considered the vast extent of the universe, and saw, with but little imagination, millions on millions of habitable worlds, I felt the force of the old objection, How could our tiny earth have been chosen for such peculiar and high honor as we read of in the gospel story?

Thomas Chalmers, in the preface to his astronomical discourses, states the difficulty in these words: “This argument involves in it an assertion and an inference. The assertion is, that Christianity is a religion which professes to be designed for the single benefit of our world; and the inference is, that God cannot be the author of this religion, for he would not lavish on so insignificant a field such peculiar and such distinguishing attentions as are ascribed to him in the Old and New Testaments.”

And then Dr. Chalmers proceeds in his able manner to overthrow both assertion and inference. He shows that it is only presumption for the infidel to claim that Christianity is designed solely for this world, and asks how he is able to tell us, “that if you go to other planets, the person and religion of Jesus are there unknown to them.” “For anything he {the infidel} can tell,” the writer continues, “the redemption proclaimed to us is not one solitary instance, or not the whole of that redemption which is by the Son of God;... the moral pestilence, which walks abroad over the face of our world, may have spread its desolation over all the planets of all the systems which the telescope has made known to us.... The eternal Son, of whom it is said that by him the worlds were created, may have had the government of many sinful worlds laid upon his shoulders.”

In this and in all the rest of his argument Dr. Chalmers, while intimating that the redemption may include other worlds, retains the belief that the actual occurrences related in the gospel took place only on this globe. Others may have heard the story, or, as he beautifully says: “The wonder-working God, who has strewed the field of immensity with so many worlds, and spread the shelter of his omnipotence over them, may have sent a message of love to each, and reassured the hearts of its despairing people by some overpowering manifestation of tenderness.... Angels from paradise may have sped to every planet their delegated way, and sung from each azure canopy a joyful annunciation, and said, ‘Peace be to this residence and good will to all its families, and glory to Him in the highest, who from the eminence of his throne has issued an act of grace so magnificent as to carry the tidings of life and of acceptance to the unnumbered orbs of a sinful creation.’”

But, as Dr. Chalmers truthfully says, it is not the infidel alone that raises this question. It is asked by many sincere believers, generally in communion with their own minds, and has disturbed, if not hindered, their faith. These brilliant discourses left me still perplexed on the main point, and I was forced to ask myself again if it was at all likely that one world could be made so unlike all others as to become the only scene of such a wonderful event as the death of the Son of God. And even if this could be made to seem probable, what an infinitesimal chance there would be that our earth would be the one chosen for this exhibition, out of the unnumbered worlds that fill the immensity of space.

As a feeble hint toward a possible solution of this difficulty, this volume is offered. The argument may not be acceptable to a single reader. I do not say that I believe it myself; but the thought has helped to satisfy my mind and may be of assistance to some other soul. I will merely say that, of course, I do not believe the analogy between any two worlds is so close as I have made it, for the purposes of the story, between Mars and the earth.

In my effort to relieve the book of dullness, I have exaggerated some of the situations, as in the treatment of the woman question for example, but the intelligent reader will easily discover whether there be anything of value remaining after the extravagance has been brushed away.

Alvan Clark & Sons, the celebrated makers of telescopic lenses, in view of their recent successes in casting larger object-glasses than was once thought possible, now assert that they can place no limit to the size these glasses may reach in the future. It is only a question of time, skill, patience, and money.

Is it, then, presumptuous to believe that the day will dawn when this world will know whether Venus or Mars is inhabited? And if either or both of them shall be found to be peopled, among the many questions of engrossing interest to be studied it seems clear to me that the most important will be the moral and spiritual condition of the inhabitants.

THE AUTHOR.