The scientist is ready to believe that contagious diseases are spread by means of the breath, but it is the providence of psychology to realize that thoughts and mental states, such as hilarity, depression, energy, or sloth, are conveyed by means of the breath. In the presence of a cold person one becomes cold, the contact of a warm-hearted person warms one; and all this is done through the breath as the medium. If an angry person were to close his breath while angry much less of his feeling would affect another. If a person who is prone to hilarity would close his breath in the presence of an expert comedian he could protect himself from being influenced by him.