the pneumatic school would rather have betrayed their country than renounce their opinions. athenaeus had also adopted much of the doctrines of the peripatetics, and besides the doctrine of the pneuma, he developed the theory of the elements much more than the methodic school had done. he recognised in the four elements the positive qualities (poiotes) of the animal body; but he often regarded them as real substances, and gave to the whole of them the name of nature of man. although the pneumatici attributed the majority of diseases to the pneuma, they nevertheless paid attention to the mixture of the elements. the union of heat and moisture was the most suitable for the preservation of health. heat and dryness give rise to acute diseases, cold and moisture produce phlegmatic affections, cold and dryness give rise to melancholy. everything dries up and becomes cold at the approach of death.