Galen and Avicenna are against this, for Avicenna says there are but three simple fevers, a fever from phlegm, one from choler and one from sanguine humour; for when it (the blood) corrupts, it causes not a simple fever, but a compound fever; for the blood is moderate, and when it heats and putrefies, the thinner part turns to choler, and the thicker to melancholy. Avicenna11 says he found much [adverse] criticism regarding this saying of Galen's, and says [moreover] that sanguine humour generates one simple fever only. I say with regard to this briefly: if vapour arise on account of the
p.25corruption of the blood, it turns to choler, and the blood putrefies by itself by reason of the antecedent cause of the combination. Of these Galen takes one view and Avicenna another.