Medicine is the science by which we learn the various states of the human body in health and when not in health and the means by which health is likely to be lost and when lost is likely to be restored back to health. In other words it is the art whereby health is conserved and the art whereby it is restored after being lost. While some divide medicine into a theoretical and a practical [applied] science others may assume that it is only theoretical because they see it as a pure science. But in truth every science has both a theoretical and a practical side.