If you are involved in politics, sooner or later someone will “prove” his point by quoting to you a line from Black’s Law Dictionary, Corpus Juris Secundum, or a similar source. He may tell you that these are “definitive” legal sources, not to be doubted.
Whatever he’s selling, don’t buy it. These sources are not definitive, and no competent lawyer treats them as such.
Black’s Law Dictionary is, as the name implies, a book of legal definitions. The definitions are largely culled from decided cases. Corpus Juris Secundum (which is Latin for “Second Body of the Law”— its predecessor was known as Corpus Juris) is an encyclopedia containing entries on legal subjects. Another widely-used encyclopedia is American Jurisprudence 2d.
All three sources can be highly useful to the practicing lawyer and sometimes for the practicing scholar—but only as starting points, not as places to end.
This is something I know about from personal experience: After attending law school, I practiced for 11 years and then served as a law professor for 25. In first year legal research courses students are taught that all three sources are useful mostly as a place to begin. By reading them, you can get a quick overview of an area preparatory to your legal research. And cases they cite offer a place to begin your investigation into the case law.
But the actual statements in those sources are always open to question. This is true for several reasons. Here are four:
* The case cited for a particular definition may be idiosyncratic or old.
* The definition may have arisen in a side comment rather than in the main holding, or contested issue, in the case.
* There may be contradictory cases in other jurisdictions.
* The authors summarizing the case or area of law may have erred.
After I wrote the lines above, I found the following at the library website of the Georgetown Law Center, the law school at Georgetown University—one of the nation’s finest. This pretty much sums things up for legal dictionaries as well as legal encyclopedias:
First, the articles can be quite useful as a general introduction to an area of law which is new to you. They provide more in-depth information than a legal dictionary, while being nearly as accessible and easy to use.
Second, encyclopedias are a way to find citations to cases and other useful materials on a particular issue. These two uses make the encyclopedias a very good place to begin major research, whether for an academic paper or a legal memorandum. However, the legal encyclopedias are not intended to be used as authoritative sources on the law in any area, and thus are not cited in briefs, memoranda, or scholarly papers.
Note: This entry was inspired by an ill-informed web posting that claimed that an entry in Black’s Law Dictionary “proved” that an Article V convention is a “constitutional convention.”