His answer to the fallacy is to say that telling a non-believer that he should study theology before he can properly discuss whether a god exists is like telling the child in the fable to study haute couture before he can properly discuss whether the Emperor is naked.
Essentially, it's a particularly ham-handed argument from authority where the position's proponent attempts to bury the opponent under a pile of detail which is largely irrelevant to the opponent's argument.
The first known instance of the use of this phrase was in response to criticism of The God Delusion by Richard Dawkins; a standard criticism was that Dawkins had not studied theology and was therefore unqualified to discuss evidence for or against the existence of God.
Which PZ Myers derisively transposed to Andersen's fable as:
“”Until Dawkins has trained in the shops of Paris and Milan, until he has learned to tell the difference between a ruffled flounce and a puffy pantaloon, we should all pretend he has not spoken out against the Emperor’s taste.
The fallaciousness of the Courtier's Reply is evident: the study of couture is only relevant to the Emperor's New Clothes if such clothes actually exist. No such knowledge is necessary to question their very existence.
Dawkins himself once said, when referring to the fact that he is not a theologian:
Likewise, the bulk of theology rests on the assumption that a god exists. Without this assumption, it has no logical basis and can be safely ignored. Using those theological arguments requires accepting the premise that God exists: that is begging the question.
As some commenters retorted, however, some arguments against the existence of God do use this assumption, as part of reductio ad absurdum demonstrations. For example, arguing that omnipotence and omnibenevolence are incompatible (or inconsistent with the existence of evil/suffering) requires assuming the existence of those attributes in some being, and then looking for logical inconsistencies. In such cases, treatises on the nature of these attributes become relevant.
Conversely, theology sometimes omits the premise that God exists. Indeed, keeping this premise in arguments for the existence of God would be circular reasoning.
 Other usage
This argument is particularly favored by anyone who fancies themselves more qualified than others on a subject. Postmodernists in particular have used it to defend the more impenetrable works of leading lights such as Derrida, Lacan, et al., from criticism from "outsiders" who "just don't understand". Meanwhile, evolution deniers (as well as denialists of other stripes) use it against scientists in an attempt to sidestep forensic evidence such as fossils and traceable physical and chemical changes in rocks and other matter.
Denunciation of this particular fallacy, however, is quite easy to misuse. Whenever one is told to read more about a subject that he disagrees on, it is easy to accuse one's contradictors of giving a "Courtier's Reply". The element of the Courtier's Reply that is being forgotten here is that it asks the questioner to "read more" about a subject that begs the question. Therefore it cannot be used, for instance, by people not liking that they are being asked to read more about global warming if they deny it. In addition, it is not fallacious to tell, for example, a creationist to read more on evolution, if they clearly do not understand what they are talking about, and are basing their evidence on false premises (such as, for example, believing that abiogenesis = evolution).
 See also
- Argument from authority
- Escape hatch
- Gish gallop
- How do you know? Were you there?
- Sophisticated theology
- Duping theologians - the Sokalability of theologians
- ↑ Pharyngula - The Courtier's Reply. The blog column by Myers that popularized the term.
- ↑  Wikipedia article on The Emperor's New Clothes story by Andersen
- ↑ Dawkins on Theology. video on YouTube
- ↑ The God Delusion: The Courtier's Reply
- ↑ Newton is alleged by some to have had an ardent interest in astrology. This is hotly disputed by others - as is the quote. Isaac Newton and Astrology