But was the classical interpretation a true index to the origin of the custom? Was it anything more than an aetiological explanation of a custom whose significance even in an early age had already become obscured by lapse of time? One thing at least has been made certain by the modern study of folklore, namely that a custom may outlive not only the idea which gave it birth but even successive false ideas which it has itself engendered in the minds of men who have sought vainly to explain it. When therefore Lucian[217] stated that ‘they put an obol in the dead man’s mouth as boat-fare for the ferryman,’ it is possible that he was recording a late and incorrect interpretation of a custom which had existed before the rôle of ferryman had ever been invented for Charon. Further if that interpretation had been in the main a literary figment, it would have been natural for the original meaning of the custom to be still remembered among the unlettered common-folk of outlying districts. There are plenty of cases in modern Greece in which different explanations of the same custom are offered in different localities. In spite therefore of the fact that one view only found expression in classical literature, there is no antecedent improbability in the supposition that an older view may have been handed down even to recent generations in the purer oral traditions of the common-folk. Once only, from a fellow-traveller in the Cyclades, did I obtain any explanation at all of the use of the coin, εἶναι καλὸ γιὰ τἀερικά[218], ‘it is useful because of the aërial ones.’ This sounds vague enough, but nothing more save gestures of uncertainty could I elicit. Was the coin useful, in his view, as a fee to be paid to ‘the aërial ones’ on the soul’s journey from this world to the next, or as a charm against the assaults of such beings? That was the question to which I sought an answer from him, but in vain. For myself I cannot determine in which sense the dark saying was actually meant. The former would accord well with one local belief of the present day, if only my informant had specified one particular kind of aërial beings who are believed to take toll of departing souls; but to this I shall return in a later section of this chapter[219]. The second interpretation of the words, however, whether they were intended in that sense by the speaker or not, furnishes what will be shown by other evidence to be the key to the origin of the custom.