“I do not,” he answered, “always act from the motives in vogue among my fellow-creatures of this planet; but why and how I differ from them it might not be well to explain.  It is for the moment of more consequence to tell you why you have been kept in some sense a prisoner here.  My neighbours, independently of general laws, are for certain reasons afraid to do me serious wrong.  While in my company or in my dwelling they could hardly attempt your life without endangering mine or those of my family.  If you were seen alone outside my premises, another attempt, whether by the asphyxiator or by a destructive animal, would probably be made, and might this time prove successful.  Till, therefore, the question of your humanity and right to the protection of our law is decided by those to whom it has been submitted, I will beg you not to venture alone beyond the bounds that afford you security; and to believe that in this request, as in detaining you perforce heretofore, I am acting simply for your own welfare, and not,” he added, smiling, “with a view to secure the first opportunity of putting your relation to our race to the tests of the dissecting table and the laboratory.”

“But my story explained everything that seemed inexplicable; why was it not believed?  It was assumed that I could not belong to Mars; yet I was a living creature in the flesh, and must therefore have come from some other planet, as I could hardly be supposed to be an inhabitant of space.”

“We don’t reason on impossibilities,” replied my friend.  “We have a maxim that it is more probable that any number of witnesses should lie, that the senses of any number of persons should be deluded, than that a miracle should be true; and by a miracle we mean an interruption or violation of the known laws of nature.”

“One eminent terrestrial sceptic,” I rejoined, “has said the same thing, and masters of the science of probabilities have supported his assertion.  But a miracle should be a violation not merely of the known but of all the laws of nature, and until you know all those laws, how can you tell what is a miracle?  The lifting of iron by a magnet—­I suppose you have iron and loadstones here as we have on Earth—­was, to the first man who witnessed it, just as complete a violation of the law of gravity as now appears my voyage through space, accomplished by a force bearing some relation to that which acts through the magnet.”

“Our philosophers,” he answered, “are probably satisfied that they know nearly all that is to be known of natural laws and forces; and to delusion or illusion human sense is undeniably liable.”

“If,” I said, “you cannot trust your senses, you may as well disbelieve in your own existence and in everything around you, for you know nothing save through those senses which are liable to illusion.  But we know practically that there are limits to illusion.  At any rate, your maxim leads directly and practically to the inference that, since I do not belong to Mars and cannot have come from any other world, I am not here, and in fact do not exist.  Surely it was somewhat illogical to shoot an illusion and intend to dissect a spectre!  Is not a fact the complete and unanswerable refutation of its impossibility?”