Between the time of Hippocrates and the 19th century, when the foundations of the scientific methods were laid, diseases were attributed to an alteration or imbalance in one of the four humors (blood, phlegm, yellow bile or black bile).
Desde o tempo de Hipócrates ata o século XIX, cando se estableceron os alicerces do método científico, as doenzas atribuíanse a unha alteración ou desequilibrio nun dos catro humores (sangue, flegma, bile amarela e bile negra).