"You put before me a great problem, my worthy President," replied the orator, smiling. "Still, men of great intelligence, such as Plutarch, Swedenborg, Bernardin de St. Pierre, and others have, if I mistake not, pronounced in the affirmative. Looking at the question from the natural philosopher's point of view, I should say that _nothing useless_ existed in the world; and, replying to your question by another, I should venture to assert, that if these worlds are _habitable_, they either are, have been, or will be inhabited." "No one could answer more logically or fairly," replied the president. "The question then reverts to this: _Are_ these worlds habitable? For my own part I believe they are." "For myself, I feel certain of it," said Michel Ardan. "Nevertheless," retorted one of the audience, "there are many arguments _against_ the habitability of the worlds. The conditions of life must evidently be greatly modified upon the majority of them. To mention only the planets, we should be either broiled alive in some, or frozen to death in others, according as they are more or less removed from the sun." "I regret," replied Michel Ardan, "that I have not the honour of personally knowing my contradictor, for I would have attempted to answer him. His objection has its merits, I admit; but I think we may successfully combat it, as well as all others which affect the habitability of the other worlds. If I were a _natural philosopher,_ I would tell him that if less of caloric were _set in motion_ upon the planets which are nearest to the sun, and more, on the contrary, upon those which are farthest removed from it, this simple fact would alone suffice to equalize the heat, and to render the temperature of those worlds supportable by beings organized like ourselves. If I were a _naturalist_, I would tell him that, according to some illustrious men of science, nature has furnished us with instances upon the earth of animals existing under very varying conditions of life; that fish respire in a medium fatal to other animals; that amphibious creatures possess a double existence very difficult of explanation; that certain denizens of the seas maintain life at enormous depths, and there support a pressure equal to that of fifty or sixty atmospheres without being crushed; that several aquatic insects, insensible to temperature, are met with equally among boiling springs and in the frozen plains of the Polar Sea; in fine, that we cannot help recognizing in nature a diversity of means of operation oftentimes incomprehensible, but not the less real. If I were a _chemist_, I would tell him that the aerolites, bodies evidently formed exteriorly of our terrestrial globe, have, upon analysis, revealed indisputable traces of carbon, a substance which owes its origin solely to organized beings, and which, according to the experiments of Reichenbach, must necessarily itself have been _endued with animation._ And lastly, were I a theologian, I would tell him that