This belief, too, had been poured mainly from Oriental sources into our sacred books and thence into the early Church, and was strengthened by a whole line of Church authorities, fathers, doctors, and saints; but, above all, by the great bull, Summis Desiderantes, issued by Pope Innocent VIII, in 1484.

This utterance from the seat of St.Peter infallibly committed the Church to the idea that witches are a great cause of disease, storms, and various ills which afflict humanity; and the Scripture on which the action recommended against witches in this papal bull, as well as in so many sermons and treatises for centuries afterward, was based, was the famous text, "Thou shalt not suffer a witch to live." This idea persisted long, and the evolution of it is among the most fearful things in human history.( 332) (332) On the plagues generally, see Hecker, Epidemics of the Middle Ages, passim; but especially Haeser, as above, III.

Band, pp.

1-202; also Sprengel, Baas, Isensee, et al.

For brief statement showing the enormous loss of life in these plagues, see Littre, Medecine et Medecins, Paris, 1875, pp.