At the conclusion of the discourse in which Dante, speaking by the mouth of Virgil, has set forth this ethical system, the poets move forward along the brink of the pit until they arrive at a spot where they can reach the lower level. The descent is rendered possible by a steep and broken slope of loose rock, which Dante compares to the great landslip between Trent and Verona, known as the Slavino di Marco.[28] Virgil explains that this was due to the “rending of the rocks” at the time of the Crucifixion. The descent is guarded by the legendary Minotaur, the Cretan monster, part bull, part man. In this connection it may be noticed that the beings suggested by classical mythology, who are met with in the division of Hell which lies between the wall of the City of Dis and the brink of Malebolge, the Minotaur, the Centaurs, the Harpies, and Geryon (as Dante conceives him), all belong to the semi-bestial class. In spite of the opinion held by some of the most eminent Dante-scholars, that Dante in his classification of sins does not follow Aristotle’s grouping of them into incontinent, malicious, and brutal, but recognises the first two only, it seems difficult not to see in this, especially when it is taken in connection with expressions scattered throughout his writings, an indication that in the sins of the seventh circle he found the equivalent of the Greek philosopher’s θηριότης--the result of giving a free range to the brutal, as distinct from the common animal, impulses. In this seventh circle, too, we first meet with _fire_ as an instrument of Divine wrath. Indeed, with the single exception of the suicides, for whom a specially significant chastisement is devised, all the sinners in this group, from the heretics in their red-hot tombs to the usurers tormented on one side by the fiery rain, and on the other by the exhalations from the deeper pit, are punished by means of heat. At the foot of the slope is a great circular plain, ringed with a river of boiling blood in which spoilers, robbers, and murderers, some famous, some obscure, are plunged more or less deeply in proportion to the heinousness of their crimes; for, like earthly streams, this has its deep and shallow. At the latter point they cross, on the back of Nessus the Centaur, and at once enter (Canto xiii.) a wood of gnarled and sere trees, in which the Harpies have their dwelling. These trees have sprung from the souls of suicides, and retain the power of speech and sensation. From one of these, who in life had been the famous statesman Peter de Vineis, Dante learns that at the judgement they will recover their bodies, like others, but will not be allowed to reassume them. The body will be hung on the tree to which it belongs. Here, as in the case of the avaricious and the wrathful, the spirits of other sinners take a part in the infliction of the punishment. The wood is inhabited by the souls of those who had wasted their substance in life, and these are