Book 2.19

A hot mind is naturally the most prone to anger: for as there are four elements, consisting of fire, air, earth, and water, so there are powers corresponding and equivalent to each of these, namely, hot, cold, dry, and moist. Now the mixture of the elements is the cause of the diversities of lands and of animals, of bodies and of character, and our dispositions incline to one or the other of these according as the strength of each element prevails in us. Hence it is that we call some regions wet or dry, warm or cold. The same distinctions apply likewise to animals and mankind; it makes a great difference how much moisture or heat a man contains; his character will partake of whichever element has the largest share in him. A warm temper of mind will make men prone to anger; for fire is full of movement and vigour; a mixture of coldness makes men cowards, for cold is sluggish and contracted. Because of this, some of our Stoics think that anger is excited in our breasts by the boiling of the blood round the heart: indeed, that place is assigned to anger for no other reason than because the breast is the warmest part of the whole body. Those who have more moisture in them become angry by slow degrees, because they have no heat ready at hand, but it has to be obtained by movement; wherefore the anger of women and children is sharp rather than strong, and arises on lighter provocation. At dry times of life anger is violent and powerful, yet without increase, and adding little to itself, because as heat dies away cold takes its place. Old men are testy and full of complaints, as also are sick people and convalescents, and all whose store of heat has been consumed by weariness or loss of blood. Those who are wasted by thirst or hunger are in the same condition, as also are those whose frame is naturally bloodless and faints from want of generous diet. Wine kindles anger, because it increases heat; according to each man's disposition, some fly into a passion when they are heavily drunk, some when they are slightly drunk: nor is there any other reason than this why yellow-haired, ruddy-complexioned people should be excessively passionate, seeing that they are naturally of the colour which others put on during anger; for their blood is hot and easily set in motion.