IdeaLogging. ''Is'' does not imply ''ought''.

<[[Brennen]]> Actually, according to the Wikipedia article, I have this wrong. "Naturalistic fallacy" was coined by G.E. Moore for something a bit more subtle:

:The naturalistic fallacy is an alleged logical fallacy, identified by British philosopher G.E. Moore in Principia Ethica (1903), which Moore stated was committed whenever a philosopher attempts to prove a claim about ethics by appealing to a definition of the term "good" in terms of one or more natural properties (such as "pleasant", "healthy", "natural", etc.).

I suspect I disagree with him, at least in part. Can you really not define a term such as "pleasure" or "healthy"? If you're interested, the article's worth a read. Anyway, see [http://www.cuyamaca.net/bruce.thompson/Fallacies/naturalistic.asp this definition]:

:The argument tries to draw a conclusion about how things ought to be based solely on information about how things are in fact. The conclusion may be about moral duties or about ideal states of affairs; but the unstated (and false) premise is that we must always accept things as they are.

Which is sort of what I was thinking. SeeAlso: IsOughtProblem.