On the basis of his daily life experiences of water waves the Swedish natural philosopher Emanuel Swedenborg (1688-1772) could use the wave metaphor to transfer the qualities of these waves to other physical phenomena such as sound waves and light waves. In the last issue of his scientific journal Daedalus Hyperboreus (1718), he published an overview of a new theory of tremulations. Swedenborg's most original idea was put forward more in detail in a manuscript of 1720. He maintained that life consists of waves or tremors of the nerves. The body is like a musical instrument. He was a typical follower of iatromechanics, describing the body as a machine with pumps, levers, bellows and so forth. Of special interest is his use of the metaphor of the circle. There are many different kinds of circulations in the body, such as the blood circulation, and respiration, which are parallels to the planetary motions.