"If bodily illness could prompt emotional disorder of the mind, the Galenic tradition makes clear that corporeal distress could affect one's woul as well. This relationship will become important in the Christian West, since many emotions fell under the heading of sin (anger, jealousy, lust, etc.). Perhaps this explains why so many medieval moral treatises so carefully emphasize patience when suffering. A real fear existed that illness may lead to sin and damnation, as in the case of the character Haukyn in Piers Plowman. Haukyn complains that when his desires are thwarted, he reacts so emotionally that he falls into an illness. This sickness proves so resistant to treatment that he eventually rejects hope in Christ's providence and turns to witchcraft to alleviate it."
From Piers Plowman, by William Langland:
'Ther is no lif that I lovye lastynge any while;
For tales that I telle no man trusteth to me.
And whan I may noght have the maistrie, swich malencolie I take
That I cacche the crampe, the cardiacle som tyme,
Or an ague in swich an angre, and som tyme a fevere
That taketh me al a twelvemonthe, til that I despise
Lechecraft of Oure Lord and leve on a wicche,
And seye that no clerc ne kan - ne Crist, as I leve -
To the Soutere of Southwerk, or of Shordych Dame Emme,
And seye that [God ne] Goddes word gaf me nevere boute,
But thorugh a charme hadde I chaunce and my chief heele.'
[13.330 - 341]