Among the numerous theories which attempt to explain the existence of the Man with the Iron Mask,[13] some have been imagined so carelessly, conceived with so much haste, and supported in so loose a manner, that they are not worthy of a serious examination, and simply to mention them will suffice to do them justice. But there are others, due to an ingenious inspiration, and sustained with incontestable talent, which, without being true, have at least many appearances of being so. Among others, the most devoid of proofs, but also the most romantic, is that which makes the Man with the Iron Mask a brother of Louis XIV. “There are many things which everybody says because they have been said once,” remarks Montesquieu.[14] This is especially true of things which border on the extraordinary and the marvellous. So, there are few persons who, on hearing the Man with the Iron Mask mentioned, do not immediately evoke a brother of Louis XIV. Whether the result of an intrigue between Anne of Austria and the Duke of Buckingham,[15] or a legitimate son of Louis XIII. and twin brother of Louis XIV., matters little to popular imagination. These are but different branches of a system which is profoundly engrafted in the public mind, and which it will not be unprofitable to overthrow separately, since it has still innumerable partisans, and touches upon the rights, moreover, the Bourbons have had to the throne of France. By whom was this widely-spread opinion first put forward? And by whom has it been revived in our own days? What proofs, or, at least, what probabilities are invoked in its support? On what recollections, on what writings, is such a supposition based? Does it agree with official documents? Is it in accord with the character of Anne of Austria or with that of Louis XIII.? Is it founded on reason? First Voltaire,[16] in his _Siècle de Louis XIV._, published in 1751, wrote the following lines, destined to excite a lively attention and to start a theory which he only completed in his _Dictionnaire Philosophique_:--