The most literal translation of chi would be motive force or life force. It is the force that makes everything happen and it is the basic thing that forms the foundation of all other things. There is no equivalent to chi in western medicine. Though it travels in the same general direction as the blood and nerve impulses, it is not the same. The closest western equivalent to chi would be like the concept of energy as it is portrayed in physics. For example, in physics everything is a different manifestation of energy and in Chinese medicine everything is a different manifestation of chi. There are two basic manifestations of chi in the human body: substance, such as organs and tissues, and function, which includes transforming, transporting, holding, raising, protecting and warming.