28 I confess that I have long been hesitating, looking on every side, shuffling, doubling Tellene perplexities; while I am ashamed to mention those Alimontian mysteries in which Greece erects phalli in honour of father Bacchus, and the whole district is covered with images of men's fascina. The meaning of this is obscure perhaps, and it is asked why it is done. Whoever is ignorant of this, let him learn, and, wondering at what is so important, ever keep it with reverent care in a pure heart. While Liber, born at Nysa, and son of Semele, was still among men, the story goes, he wished to become acquainted with the shades below, and to inquire into what went on in Tartarus; but this wish was hindered by some difficulties, because, from ignorance of the route, he did not know by what way to go and proceed.
One Prosumnus starts up, a base lover of the god, and a fellow too prone to wicked lusts, who promises to point out the gate of Dis, and the approaches to Acheron, if the god will gratify him, and suffer uxorias voluptates ex se carpi. The god, without reluctance, swears to put himself in his power and at his disposal, but only immediately on his return from the lower regions, having obtained his wish and desire. Prostmmus politely tells him the way, and sets him on the very threshold of the lower regions.
In the meantime, while Liber is inspecting and examining carefully Styx, Cerberus, the Furies, and all other things, the informer passed from the number of the living, and was buried according to the manner of men. Evius comes up from the lower regions, and learns that his guide is dead. But that he might fulfil his promise, and free himself from the obligation of his oath, he goes to the place of the funeral, and — “ficorum ex arbore ramum validissimum praesecans dolat, runcinat, levigat et humani speciem fabricatur in penis, figit super aggerem tumuli, et postica ex parte nudatus accedit, subsidit, insidit. Lascivia deinde surientis assumptâ, huc atque illuc clunes torquet et meditatur ab ligno pati quod jamdudum in veritate promiserat.”
Source: Against the Heathen (New Advent)