Naturalist fallacy tis defined as the error of defining what is good in terms of what is observable. For example: What's typical is normal; what's normal is good. According to G. E. Moore, Naturalistic Fallacy, is any argument which attempts to define the good in any terms whatsoever, including naturalistic terms; for Moore, Good is simple and indefinable. Some philosophers, most notably defenders of naturalism, have argued that Moore and others are wrong and that such arguments are not necessarily fallacious.