A federal judge in Boston has ruled that the Defense of Marriage Act (DOMA) passed by Congress (427 members voted in favor) and signed into law by President Clinton in 1996 cannot take precedence over a Massachusetts law allowing same-sex marriage. The ruling again raises serious questions about the origin and purpose of law. But before we get to that larger question, the "logic" of Judge Joseph L. Tauro's ruling should first be examined. Judge Tauro's decision flies in the face of what the federal government has claimed and is claiming in at least two other significant cases. In 1973,...