People indifferent to physiology might attribute some of love's magic results to "inspiration," to "spiritual uplift" and other vaguely conceived factors of a romantic and sentimental nature.
I am always reminded when encountering such explanations in the literature of love, of the nuptial flight of the bee.
When a male and female bee fall in love, they both fly to a dizzy height in the direction of the sun and there perform the sexual union. To an unscientific mind of the Maeterlinckian type, there might be in that picture a beautiful symbol of love's exaltation.
The cold blooded scientist, on the other hand, will simply tell us that erotic excitement in the bee produces a large amount of irritating phototropic materials which compel the bees to fly toward the source of light.
At the end of the sexual act, the production of phototropic materials ceases and the bees come back to earth ... like lovers tired of each other.
In love the conqueror feels like a conqueror and is a hard adversary to defeat. Like the amorous bees which can reach, physically speaking, heights which they would never dream of exploring when out of love, the successful lover can rise to infinite heights physically and mentally.
The Unsuccessful Lover, on the other hand, may be, in extreme cases, a pitiful individual to contemplate.
The humiliation of defeat and the fear of other defeats, the starvation of all the senses which the love object would have gratified, produce a depression which stops temporarily all the life activities.
Appetite is lacking and there may be nausea and vomiting; diarrhea or constipation replace the normal activities of the intestine, thereby inducing weakness or autointoxication which, through a vicious circle, still increase the depression. The heart action is disturbed, which increases the uneasiness of the sufferer, his breathing is difficult, causing much sighing, the surface capillaries are emptied of blood, producing a morbid pallor, etc.
A person in that condition is incapable of continued effort in any direction. The stoppage of all the life functions induces a sense of worthlessness. The fear of defeat not infrequently drives the sufferer to suicide, which is a symbolic attempt at returning to the safest condition in which the organism ever found itself: death, the return to uterine life, to mother earth, etc.