In opening his second book John subscribes to the proverb that he who trusts in dreams and auguries will never be secure and asks--like Cicero in his _De divinatione_[468]--what possible connection there can be between sneezes, yawns, and other such things accepted as signs and the events which they are supposed to signify. With Isidore and Augustine[469]--although he names neither--he rejects those empty incantations and superstitious ligatures which the entire medical art condemns, although some call them _physica_.[470] This seems like an admirable approach to an attitude of rational criticism, but John after all may be merely repeating others’ statements like a parrot, and he entirely spoils its effect by what he goes on to say. He believes that the cloak of St. Stephen raised the dead, and that such practices as saying the Lord’s prayer while plucking or administering medicinal herbs, or wearing or hearing or repeating the names of the four evangelists,[471] are not only allowable but most useful. He adds further that the force of all omens depends upon the faith of the recipient. [Sidenote: Divine and natural signs.] Although opposing faith in omens and augury, John admits that God provides signs for His creatures, such as those of the weather which sailors and farmers learn by experience and the birds are not ignorant of, or the indications by which doctors can prognosticate the course of diseases. Unfortunately the demons also are able to show signs and thus lead men astray. Mention of signs which preceded the fall of Jerusalem then leads John into a digression for several chapters concerning the horrors of the siege itself and Vespasian and Titus, a passage which was very likely inserted because Henry II and Becket were at that very time engaged in laying siege to Toulouse. [Sidenote: Miracle and occult virtue.] Returning to the subject of signs, John interprets the verse in Luke, “There shall be signs in sun and moon and stars” as having reference to unnatural signs, and the obscuration of the sun during Christ’s passion as not a natural eclipse.[472] John explains that by nature he means “the accustomed course of things or the occult causes of events for which a reason can be given.”[473] If, however, we accept Plato’s definition of nature as the will of God there will be no unnatural events. But John would distinguish between the gradual growth of leaves and fruit on tree or vine by means of roots drawing nutriment from earth’s vitals and sap produced within the trunk, which is indeed marvelous and has the most occult causes, and the performance of the same process without any interval of time, which he regards as a miracle and of a divine height which transcends our understanding. After drawing this distinction between divine miracle and wonders wrought by occult virtues in nature John returns again to the subject of signs. [Sidenote: Interpretation of dreams.]