President Bush's promise to appoint originalist justices like Scalia and Thomas invites the question: What is this peculiar creature, the originalist?

The term "originalism" identifies the traditional, common-sense principle that the meaning of various provisions of the Constitution (and of other laws) is to be determined in accordance with the meaning they bore at the time they were promulgated. The status of originalism as the only legitimate method (or class of methods) of constitutional interpretation inheres in the very nature of the Constitution as law. As Chief Justice Marshall explained in his landmark 1803 opinion in Marbury v. Madison, the Constitution is "committed to writing" so that its "limits may not be mistaken or forgotten." To disregard its limits is to "reduce[] to nothing what we have deemed the greatest improvement on political institutions -- a written constitution."

It is significant that the term "originalism" appears to be of relatively recent vintage. The reason for this is not that there is anything novel about originalism. Precisely the opposite. Until recent years, originalism had been so unchallenged as constitutional orthodoxy that there was no reason to develop a term that would distinguish it from any rival. As Justice Scalia has put it, "in the past, nonoriginalist opinions have almost always had the decency to lie, or at least to dissemble, about what they were doing." But the rise of the "living Constitution" -- the Orwellian euphemism that liberal activists have used to pretend that the Constitution has somehow "grown" to entrench forever their own policy preferences -- made necessary a label for what everyone had previously recognized as elementary.

An analogous semantic development might illustrate this point. According to the Oxford English Dictionary, the term "heterosexual" came into usage barely a century ago. This is obviously not because heterosexuals did not previously exist, but rather precisely because what we now call heterosexuality had been widely understood to be normative.

Here's my simple single-question multiple-choice test for whether you are an originalist:

Q. The Constitution provides, as one of the criteria to be eligible to become president, that a person must be a "natural born Citizen" (or, alternatively, in a provision that long ago ceased to apply to any living persons, "a Citizen of the United States, at the time of the Adoption of this Constitution") How would you figure out what the phrase "natural born Citizen" means?

(A) You would determine that the "natural born Citizen" requirement, whatever it means, is obviously a relic of a benighted and xenophobic past, a past that "evolving standards of decency," as reflected in modern European electoral practices, requires be abandoned. It simply isn't fair, you would conclude, that any candidates should be excluded by such an arbitrary requirement from running for president. You would invoke "the right to define one's own concept of existence, of meaning, of the universe, and of the mystery of human life" as you instead substituted your own arbitrary criteria for eligibility.

(B) You would try to discern the current meaning of the phrase "natural born Citizen." Its closest connection would appear to be to the concept of natural childbirth. Therefore, you would conclude that only those whose mothers did not use drugs during birth satisfy the requirement.

(C) You would look to literature as your guide. Macbeth finds great comfort in the promise that "none of woman born/Shall harm" him. But his comfort proves unwarranted when Macduff, who "was from his mother's womb/Untimely ripp'd," kills Macbeth. It follows that anyone whose birth was by Cesarean section is not a "natural born Citizen."

(D) You would try to determine the public meaning of the "natural born Citizen" requirement at the time that the Constitution was adopted.

If it is obvious to you that the proper response is (D), then you are an originalist. If you think that the answer might be (A), then you are probably Justice Stevens, O'Connor, Kennedy, Souter, Ginsburg, or Breyer.

For what it's worth, although I haven't researched the issue, my own strong intuition is that the phrase "natural born Citizen" is meant to identify those persons who were citizens at birth, by virtue of the citizenship laws in effect at the time, as opposed to those who were naturalized after birth. And, any of you lawyers out there, please don't tell me that the issue isn't, or might not be, justiciable; my question is how to determine what the provision means, not whether courts would in fact decide it.

Some theorists, of course, contend that certain constitutional provisions, like "due process of law" or "cruel and unusual punishments," are, to various degrees, open-ended, and deliberately so, and that these provisions were understood to delegate considerable discretion to judges to supply their meaning over time. This short essay is not the occasion to examine the validity of those claims or their compatibility with American principles of representative government. For present purposes, it suffices to observe that these theorists either expressly acknowledge or implicitly concede the legitimacy of originalism and merely contest with other originalists what originalism yields.

I very much suspect that many English speakers two or three generations ago were a bit nonplussed to be labeled "heterosexuals." I hope that, if you have just discovered that you are an originalist, your reaction is more like the delight of Molière's Monsieur Jourdain on learning that he had been "speaking in prose" all his life without knowing it.

– Edward Whelan is president of the Ethics and Public Policy Center and is a regular contributor to National Review Online's "Bench Memos" blog on judicial nominations.