“The relation between is/ought, fact/value, objectivity/normativity, and science/ethics all touch on the notion of the naturalistic fallacy. In general terms, this notion is an expression of the philosophical argument that one cannot infer from the one to the other; one cannot infer from is to ought, nor can one make an inference from scientific observations to ethical arguments. Any such attempt means committing the naturalistic fallacy. Historically, David Hume (1711–1776) and G. E. Moore (1873–1958) were the primary advocates of the invalidity of a moral argument based on such an inference.
“. . . The term naturalistic fallacy goes back to G. E. Moore, who in Principia Ethica (1903) argued that the notion of the good could not be based by reference to nonmoral entities. The good is a simple, indefinable concept, not composed by other nonmoral parts. This is precisely the problem of the naturalistic fallacy, which points to nature or to some other nonmoral entity and argues that this serves as the basis of moral normativity. Thereby the difference between these parts is ignored, as is the invalidity of inferring from one to the other. By committing the naturalistic fallacy, one would substitute “good” with a nonmoral property.” (continue article)
— Ulrik B. Nissen in Encyclopedia of Science and Religion
* It would seem that Sam Harris’s latest book, The Moral Landscape: How Science Can Determine Human Values, largely falls into the category of the naturalistic fallacy.