And first, we must learn to control our thoughts and make them go where we send them. In too many cases thoughts wander here and there, with no power governing and guiding them.
When we are sauntering in the wood we sometimes come upon pathways, and we know at once that many, many footsteps of men or animals have been needed to make the paths. If those who walked here had wandered each in his own way, no path would have been made. One pair of feet going often over the same ground will make a path. So the thoughts, traversing the same areas of brain, will make records on the brain-cells which we may call paths. Every time a thought follows the same line it creates a deeper impression, and makes it easier to go over the same territory again. In this way habits are formed. If the thoughts are good, the habits will be good; if evil, the habits will be bad.
It is not hard to understand how much easier it is to form a habit than to overcome it. The emotions, like the thoughts, create habits; but, more than this, they create actual physical conditions.
It was my pleasure and profit once to have a conversation with Professor Gates in his laboratory, and he showed me an instrument wherein he condenses the breath. He then subjects it to a chemical reagent, and by the precipitate formed he knows what was the mental condition of the individual, whether he were angry, sorrowful or remorseful. In five minutes after a fit of anger he finds the excretory organs beginning to throw out the poison which anger has created. Only five minutes suffice to create the poison, but half an hour is none too much to eliminate it.
Think what must be the bodily state of one who is constantly irritated or angry, who feels jealousy, hatred, or revenge. With body poisoned by these malevolent passions he cannot feel well, for his physical organs cannot do good work unless fed by pure blood. Professor Gates finds that the benevolent emotions create life-giving germs in the body; so, to love others is not only helpful to them, but it also gives us new life.
Anger, worry, hatred, jealousy, are suicidal emotions. We cannot for our own sakes afford to indulge in them, while from selfish reasons alone we should be incited to kindness, generosity, sympathy, and love.