374. That with some, jealousy is from various mental sicknesses is no secret in the world; for there are jealous men who continually think of their wives as unfaithful, believing them to be harlots, and this merely on hearing or seeing that they talk amicably with men or about men. There are mental blemishes which induce this infirmity, the first among which is a suspicious fantasy. If long cherished, this brings the mind into societies of like spirits, from which it can be delivered only with difficulty. Jealousy also gives itself added strength in the body, by the serum and thence the blood becoming viscous, tenacious, thick, sluggish, and acrid. Moreover, it is augmented by lack of the virile powers, this rendering the mind unable to be raised above its suspicion; for their presence elevates, and their absence depresses, this absence causing the mind to droop, collapse and languish. It then immerses itself in that fantasy ever more and more until it becomes insane; and this insanity has its outlet in the delight of upbraiding and, so far as allowed, of reviling.