[80] Sismondi (_Literature of the South of Europe_) has observed of the greatest epic of the Middle Age, that 'Dante, in common with many fathers of the Church, under the supposition that paganism, in the persons of the infernal gods, represented the fallen angels, has made no scruple to adopt its fables.' Tasso, at a later period, introduces the deities of heathendom. In the _Gerusalemme Liberata_ they sit in council to frustrate the plans and destroy the forces of the Christian leaders before Jerusalem (iv). Ismeno, a powerful magician in the ranks of the Turks, brings up a host of diabolic allies to guard the wood which supplied the infidels with materials for carrying on the siege of the city (xiii.). And the masterpieces of art of Guido or Raffaelle, which excite at once admiration and despair in their modern disciples, consecrated and immortalised the vulgar superstition. Glanvil's conjectures on the cause of the _comparative_ rarity of demoniac and other spiritual apparitions in general may interest the credulous or curious reader. ''Tis very probable,' reasons the Doctor, 'that the state wherein they are will not easily permit palpable intercourses between the bad genii and mankind: since 'tis like enough their own laws and government do not allow their frequent excursions into the world. Or it may with great probability be supposed that 'tis a very hard and painful thing for them to force their thin and _tenuious_ bodies into a visible consistence, and such shapes as are necessary for their designs in their correspondence with witches. For in this action their bodies must needs be exceedingly compressed, which cannot well be without a painful sense. And this is, perhaps, a reason why there are so few apparitions, and why appearing spirits are commonly in such a hurry to be gone, viz. that they may be delivered of the unnatural pressure of their tender vehicles,[81] which I confess holds more in the apparition of good than evil spirits ... the reason of which probably is the greater subtlety and tenuity of the former, which will require far greater degrees of compression and consequently of pain to make them visible; whereas the latter are feculent and gross, and so nearer allied to palpable existences, and more easily reducible to appearance and visibility.'[82] [81] So specious a theory must have occurred to, and its propriety will easily be recognised by, the spirit and ghost advocates of the present day. [82] _Sadducismus Triumphatus._ Considerations about Witchcraft. Sect. xi.