Durkheim defined religion as: "a unified system of beliefs and practices relative to sacred things, i.e., things set apart and forbidden—beliefs and practices which unite in one single moral community called a Church, all those who adhere to them."In this definition, Durkheim avoids references to supernatural or God. Durkheim argued that the concept of supernatural is relatively new, tied to the development of science and separation of supernatural—that which cannot be rationally explained—from natural, that which can. Thus, according to Durkheim, for early humans, everything was supernatural. Similarly, he points out that religions that give little importance to the concept of god exist, such as Buddhism, where the Four Noble Truths are much more important than any individual deity. With that, Durkheim argues, we are left with the following three concepts: