_The Lives of the Philosophers_, by Diogenes Laertius, is a very familiar title and even book. But it is at the same time almost to be regarded and taken as the prototype of literary works based, with every wish on the part of the writer to be accurate and veracious, on hearsay and tradition. Diogenes is the Greek Aubrey. His transactions in conjecture and conflicting opinions are marvellously large; and, as a consequence, his text abounds with uncertainty and confusion. One is reminded nearly at every page of the story of the Southern gentleman who once undertook a journey to the Highlands of Scotland to inquire for _Meester Grant_; and, singularly enough, the source of the difficulty is very much the same. Diogenes made himself the biographer of a people whose choice of names was limited, and among whom the same name was of common occurrence. So long as the men themselves lived, it signified little or nothing; but if they became famous and historical, or if one out of several did so, the facilities for mixture of identity were, as a matter of course, immense. This circumstance, which is not casual, but is the rule _not_ proving the exception, sensibly diminishes the value of the _Lives_ as an authority; and it is easy to see how the taint has been communicated to the best of our modern Cyclopædias, where the contributors of articles are obliged to own repeatedly, that some fact or other is attributed by half a dozen ancient writers to as many different persons of the same name, nationality and approximate period. I shall pass over the circumstance that the biography of Diogenes is almost as involved and obscure as his text, for I am merely dealing with him and his celebrated book in a prefatory way. I should be very sorry indeed to undervalue such a unique and fascinating magazine of gossip and tradition; nor have I at present to concern myself with the contradictory statements, not only about men of inferior fame, but about such prominent characters as Thales and Plato; and, besides, in relation to the most important events of their careers and the points most vital to their reputation. Take, for instance, in the account of Thales, the well-aired anecdote of the _Golden Tripos_. I quote from the old English translation. “As for what is recorded,” says he, “concerning the _Tripos_ found out by the fishermen, and sent to the _Wise Men_ by the _Milesians_, it still remains an undoubted Truth.” He then narrates this “undoubted truth”; and when he has done so, he successively furnishes three other versions materially differing; and we have to go only a step further, when we encounter a saying of Thales as to his gratitude for three things--that he was a man, and not a beast; that he was a man, and not a woman; and that he was a Greek, and not a barbarian--which, it seems, is as likely to have been a saying of Socrates. We have all heard something very similar of Dr. Parr and Sir James Mackintosh.