Several of the apocryphal books show a great advance in the theory of retributive justice in the future life. The so-called _Apocalypse of St. Peter_ is known to have existed in Syria and Egypt before the middle of the second century, and to have been admitted by several of the Fathers into the Canon, side by side with the Book of Revelation. Paradise is here described in much the same manner as the Greek Elysium--as a radiant place, full of flowers, fruit, and sweet odours, etc. The pains of Hell are set out with a more than common minuteness, and with a greater attention to a kind of _lex talionis_, so to speak, whereby the nature of the punishment is analogous to that of the crime, than is found in most of the Christian descriptions prior to Dante. Hell is represented as a place full of lakes of fire and burning mud, over which those who had blasphemed ‘the way of righteousness’ are suspended by their tongues, and adulterers by the hair, while in them wallow the perverters of righteousness. Blasphemers gnawed their lips, and had red-hot iron over their eyes; false witnesses had tongues of fire in their mouths, which they kept on chewing; rich misers, in filthy rags, rolled upon red-hot pebbles, sharper than sword or spit; usurers stood up to their knees in pitch, blood, and boiling mire; those guilty of unnatural crimes were hurled from a cliff and driven up again, to be again cast down. A similar vision of the Otherworld, though differing in plan and in many details, is contained in the _Revelation of St. Paul_, written about the year 380 A.D. Apparently the author of the _Fis Adamnáin_ had this work in his mind when referring in ch. 2 to the Revelation that had been vouchsafed to St. Paul, for the Apostle’s own mention of his Vision of the Third Heaven contains no description of the Otherworld. Moreover, it is impossible not to be struck by the resemblance between the Irish author’s description of the manner in which the souls were received upon their arrival at the seventh Heaven (ch. 19), and the corresponding account in the _Apocalypse of St. Paul_: ‘And the good angels who had received the soul of the righteous man saluted it, as being well known to them,’ etc.[90] And so of the judgments passed upon the sinners in like manner. There are also several details given by the apocryphal writer concerning the pains of Hell, which are repeated in a closely similar form in the _Fis Adamnáin_: _e.g._ the immersion of some of the wicked in a murky river, the imprisonment of others in a brazen wall wrapt in flames, etc.