Even though most Americans know little about the Supreme Court, they generally understand that it is important. After all, the Supreme Court is regarded as the final interpreter of the Constitution. Barring amendment, Supreme Court decisions on the Constitutionality of abortion, flag burning, and gun control are the law of the land -- no matter what Congress, the president, or the states have to say.

However, the Constitution does not explicitly bestow this final authority on the Supreme Court. Rather, Article III gives the Court "the judicial power," which means the power to decide legal cases that come before it.

When the Supreme Court hears a case, the Justices must decide which of the two parties at odds wins. Usually they decide who is victorious based on whether someone has been harmed by a government law or action that is contrary to the Constitution. If a person has been harmed by an unconstitutional law or action, he wins -- because any law or action contrary to the Constitution is void. But how can a Justice determine if a law or action is unconstitutional?

Of course, all Justices begin with the Constitutional text. If a law clearly violates some obvious provision of the Constitution, the law is void. But in some cases, it is not clear whether a law violates the Constitution because it is not clear what the Constitution means. For example, the Fourth Amendment prohibits "unreasonable" searches and seizures while the Fifth Amendment forbids depriving someone of "liberty" without due process of law. "Unreasonable?" "Liberty?" How does a Justice know what these words mean?

At this point, a Justice must interpret the text. There are two basic approaches to Constitutional interpretation. The first is often referred to as the "living Constitution" approach. It is rooted in the belief that the Constitution has to "keep up with the times," that the text must be interpreted in light of society’s changing values.

Perhaps the best-known advocate of this approach was William Brennan, one of the most famous liberals on the Court in the last 25 years. In one example of his "living Constitution" approach, Justice Brennan went so far as to argue that the death penalty "is under all circumstances cruel and unusual punishment prohibited by the Eighth and Fourteenth Amendments." He said this even though the death penalty has been around since the Founding and even though, for example, the Fifth Amendment specifically requires a grand jury indictment for any "capital" crime. Despite the historical and textual indications that capital punishment is Constitutional, Justice Brennan claims that our values have progressed so much that we no longer should be guided by outmoded ways of Constitutional thinking. In his view, a Justice should decide based on his "enlightened" understanding of society’s changing values rather than on the plain indications of the text.

Fortunately, a number of Justices are reluctant to substitute their personal opinions for the Constitutional text. These Justices use a second approach to understand the meaning of the Constitution; they look to the "original intent" of the Constitution. The most prominent branch of this approach is often called the "text and tradition" method of interpretation, and is favored by conservative Justices like William Rehnquist and Antonin Scalia. To understand the word "liberty," for example, they say that Justices should examine how the word was used in the Founders’ writings and in the tradition of laws dating back to the Founding.

While this approach has the great benefit of making the Justices defer to well-established legal and Constitutional traditions, it also has some problems. What if, for example, the Founders’ writings seem unclear or contradictory on some issue? How then can a Justice follow their intentions?

More importantly, what if aspects of our legal tradition seem unjust? For example, in 1967 the Supreme Court had to decide whether a Virginia law prohibiting marriage between blacks and whites violated the Constitution. The Justices had to resolve this question: Is it part of our Constitutional "liberty" to marry a person of another race if we so choose? Since the Founders’ written views on this subject are not clear and since there was a long tradition of laws prohibiting such marriages, a "text and tradition" judge would have to conclude that such laws do not violate the original intent of the Framers and therefore are constitutional.

This is where Justice Thomas comes in. He represents a vital but almost forgotten branch of original intent jurisprudence -- the "natural law" approach. He agrees that Justices should give great deference to legal tradition and that they must follow the original intent of the Constitution. Unlike Rehnquist or Scalia, however, he claims that the Framers’ original intent is not so much located in particular writings like The Federalist Papers or in laws dating back to the Founding, but above all in the document that gave birth to our country: the Declaration of Independence.

In his view, "the ’original intention’ of the Constitution" is to fulfill "the ideals of the Declaration of Independence." As we know, the Constitution was originally intended to replace the Articles of Confederation and create "a more perfect Union." For the Founders, "a more perfect Union" meant a Union that more perfectly embraced the principles for which they risked their "Lives," "Fortunes," and "sacred Honor" in the Revolutionary War. As Justice Thomas points out, these principles are the "ideals of the Declaration of Independence." Hence he draws the reasonable conclusion that to understand the original intent of the Constitution, we must first understand the principles of the Declaration.

According to the Declaration, America’s basic moral and political principles are found in "the laws of Nature and of Nature’s God." Justice Thomas would argue, for example, that a member of the Supreme Court can only discern whether the Constitution’s guarantee of "liberty" overrides laws preventing interracial marriage by understanding the nature of the liberty given to every person by natural law -- what the Declaration calls the "unalienable" right to liberty with which all people, regardless of race, "are endowed by their Creator." He consistently has argued that because our rights come from our nature and not our race, the law should not classify people or forbid actions based on race. (Hence Justice Thomas believes that both anti-interracial marriage laws and affirmative action programs violate the "colorblind" spirit of the Constitution.)

This approach to Constitutional interpretation places a high duty on the Supreme Court Justices -- they must not only be lawyers thoroughly versed in case law, but also students of the natural law (or at least students of the best teachers of the natural law). They must do more than examine legal traditions or writings of the Founders; they must carefully use their God-given reason to comprehend and apply the "self-evident" truths that form the basis of the Constitutional text they are called to interpret.

To many of us, Justice Thomas’ view seems like good common sense -- the Declaration declares our fundamental principles and the Constitution forms a government designed to put those principles into practice. But his approach is ridiculed or denigrated by many of today’s self-appointed guardians of law, including some of America’s most prominent lawyers, judges, and law school professors. They call him "naive" or even "dangerous."

Fortunately, though, the natural law approach has held a high place in American jurisprudence. Thomas Jefferson and James Madison agreed, for example, that the best guide to the Constitution is the Declaration of Independence and its philosophy of natural rights. This view was common at the Founding; so common, in fact, that early Supreme Court decisions, like Calder v. Bull (1798), claimed that even laws "not expressly restrained by the Constitution" should be struck down if they violate natural rights. Nor was this view limited to the Founding era. Before and during the Civil War, for example, Abraham Lincoln repeatedly appealed to the legal authority of the Declaration in his fight against slavery.

In the end, let us hope that Justice Thomas will be remembered for leading a revival of America’s tradition of natural law on the Supreme Court on the Supreme Court. This would be a great service to our Republic, for it has the power to restore the Court’s understanding of the original meaning of the Constitution. It is up to us, however, to rise to the challenge he sets for America’s citizens -- to revive in our own hearts and minds a true understanding of the deepest principles of the Constitution and Declaration of Independence. For only then can we ensure that America’s experiment in "government of the people, by the people, and for the people" will be passed on to future generations. Only then can we be sure that we will not forget the principles for which so many have fought and died -- the principles that make us Americans.

Jeffrey Sikkenga is an Assistant Professor of Political Science at Ashland University and an Adjunct Fellow at the Ashbrook Center.