[Galen's intermittent fever].

In his comprehensive Oeuvre, Galen of Pergamon, who interpreted and perfected Hippocratic medicine, made many times and in various contexts mention of the intermittent fevers, among which malaria undoubtedly held a prominent position. The following article gives an outline of Galen's theoretical concept of this infectious disease, which was of utmost importance for the history of Italy. Galen describes three different types of intermittent fevers, of which, according to his theory of humoural pathology, each one is caused by a special humour with its respective qualities. Thus the quotidian fever is caused by phlegm, the tertian fever by the yellow bile and the quartan fever by the black bile. Apart from the three basic types of fever Galen describes a number of other mixed forms which can either be developed out of identical types or out of different ones. A mixture of a special kind is febris semitertiana: a continuous quotidian is accompanied by an intermittent tertian. It is the worst and most dangerous of these fevers. On the whole Galen's theory of malaria is a paradigm for his forming the reality of diseases on the basis of his pre-knowledge of humoural pathology into a closed system of theory.