The maddest dreams of the fancy have some ground of reason, and who knows if everything that the imagination of man can conceive either has not already happened, or is not now happening or will not happen some time, in some world or another? The possible combinations are perhaps infinite. It only remains to know whether all that is imaginable is possible. It may also be said, and with justice, that much of what I am about to set forth is merely a repetition of ideas which have been expressed a hundred times before and a hundred times refuted; but the repetition of an idea really implies that its refutation has not been final. And as I do not pretend that the majority of these fancies are new, so neither do I pretend, obviously, that other voices before mine have not spoken to the winds the same laments. But when yet another voice echoes the same eternal lament it can only be inferred that the same grief still dwells in the heart. And it comes not amiss to repeat yet once again the same eternal lamentations that were already old in the days of Job and Ecclesiastes, and even to repeat them in the same words, to the end that the devotees of progress may see that there is something that never dies. Whosoever repeats the "Vanity of vanities" of Ecclesiastes or the lamentations of Job, even though without changing a letter, having first experienced them in his soul, performs a work of admonition. Need is to repeat without ceasing the _memento mori_. "But to what end?" you will ask. Even though it be only to the end that some people should be irritated and should see that these things are not dead and, so long as men exist, cannot die; to the end that they should be convinced that to-day, in the twentieth century, all the bygone centuries and all of them alive, are still subsisting. When a supposed error reappears, it must be, believe me, that it has not ceased to be true in part, just as when one who was dead reappears, it must be that he was not wholly dead.