"The affect structure of a man is a whole. We may call particular instincts by different names according to their different directions and functions, we may speak of hunger and the need to spit, of the sexual drive and of aggressive impulses, but in life these different instincts are no more separable than the heart from the stomach or the blood in the brain from the blood in the genitalia. They complement and in part supersede each other, transform themselves within certain limits and compensate from each other, a disturbance here manifests itself there."

It's very interesting to see how manners and civility have changed throughout history. People in general have changed in so many ways throughout history. Human nature itself has changed. I believe that people in general have changed their human nature to be more civil and less aggressive. It went from spitting being acceptable, to...