Man is said to be a rational being, but his thought is directed mainly against the problems of nature, much more rarely against his own problems.  It is for emotion that we live, for emotion in the wide sense of pleasure and pride.  What guides us in our conduct is desire, and desire in the last analysis is based on the instincts and the allied emotions,—­hunger, sex, property, competition, cooeperation.  The intelligence guides the instincts and governs the emotions, but in the case of the vast majority of mankind is swept out of the field when any great decision is to be made.

We are accustomed to thinking of emotion as a thing purely psychical,—­purely of the mind, despite the fact that all the great descriptions and all the homely sayings portray it as bodily.  “My heart thumped like a steam engine,” or “I could not catch my breath”; “a cold chill played up and down my back”; “I swallowed hard, because my mouth was so dry I could not speak.”  And the Bible repeatedly says of the man stricken by fear, “His bowels turned to water,” with a graphic force only equaled by its truth.

William James, nearly simultaneously with Lange, pointed out that emotion cannot be separated from its physical concomitants and maintain its identity.  That is, if we separate in our minds the weak, chilly feeling, the dry mouth, the racing heart, the sharp, harsh breathing, and the tension of the muscles getting ready for flight from the feeling of fear, nothing tangible is left.  Similarly with sorrow or joy or anger.  Take the latter emotion; imagine yourself angry,—­immediately the jaw becomes set and the lips draw back in a semi-snarl, the fists clench and the muscles tighten, while the head and body are thrust forward in what is, as Darwin pointed out, the preparation for pouncing on the foe.  Even if you mimic anger without any especial reason, there steals over you a feeling not unlike anger.

In a famous paragraph James essentially states that instead of crying because we are sorry, it is fully as likely that we are sorry because we cry.  So with every emotion; we are afraid because we run away, and happy because we dance and shout.  In other words he reversed the order of things as the everyday person would see it; makes primary and of fundamental importance the physical response rather than the feeling itself.

This has been widely disagreed with, and is not at all an acceptable theory in its entirety.  Yet modern physiology has shown that emotion is largely a physical matter, largely a thing of blood vessels, heartbeat, lungs, glands, and digestive organs.  This physical foundation of emotion is a very important matter in our study of the housewife as of every other living person.  For it is especially in the emotional disturbance that the origin of much of nervousness is to be found, and that on what may be called the physical basis of emotion.

What can emotion produce that is pathological, detrimental to well-being?  We may start with the grossest, simplest manifestations.  It may entirely upset digestion, as in the vomiting of disgust and excitement.  Or, in lesser measure, it may completely destroy the appetite, as occurs when a disturbing emotion arises at mealtime.  This is probably brought about by the checking of the gastric secretions.  (Cannon’s work; Pavlow’s work.)