Naturalism, or material monism (materialism), says that there exists only one kind of being, matter (broadly defined as extended and non-conscious and therefore includes some contemporary terms like energy and space). There are many justifications given for this belief, such as “that’s all I can see” (naïve realism), or “it is what everyone accepts” (common sense realism), for some there is a mystical connection with the physical universe (intuitive realism), it doesn’t multiply unnecessarily stories about gods and the supernatural (critical realism). Perhaps the most pernicious and harmful (to the reputation of science) is “this is the view that science has proven.” This is harmful to science because science does not prove basic beliefs, but instead deals with experience and appearances. All scientists may be able to agree on the measurement of experiences or data, but the difficult problem is in how to interpret this information.