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1L Survival Guide: Secondary Authorities

Basic Law Library Survival Information

Legal Authorities

An authority is a statement of law used to support a legal proposition.

Authorities are divided into primary and secondary; mandatory and persuasive.

Primary Authority

Primary authority is the law itself.  This includes constitutions, statutes, published opinions, regulations, treaties and court rules.

Secondary Authority

Secondary authority is commentary on the law.  Treatises, Restatements, journal articles, A.L.R. Annotations, legal encyclopedias, hornbooks, etc. all comprise secondary authority

Mandatory Authority

Mandatory authority is primary authority that binds a court.  The court must follow mandatory authority when reaching its decision.

Persuasive Authority

Persuasive authority does not bind a court.  A court may follow persuasive authority when reaching its decision when it is persuaded to do so.

Secondary Authorities

American Law Reports (A.L.R.)

Unique to law, an ALR annotation covers a single, narrow legal issue based on a lead case that exemplifies the issue.  Titles for annotations are often lengthy and detailed.  The annotation also covers cases from all jurisdictions on the point of law under scrutiny.  It's a good place to find more cases on very narrow legal issues.


Black's Law Dictionary or any law dictionary should be one of the books you purchase and have nearby when you are studying.  Learning the law is largely about learning a new vocabulary. A Black's Law Dictionary is available in the Reference Area near the photocopier.


Technically, a Digest is NOT an authority (you cannot cite to a Digest); it is a case finding aid, but a really useful one.  The Digest System (created by West Publishing) is a topic and key number system.  First you find the topic and second, you find a refinement of the topic in the topic's table of contents. The number associated with the refined topic is called the key number.  Sometimes students mistakenly call this the "Key Number System," but that is not accurate since a key number only exists within a topic. Digest sets also include several volumes called "Words and Phrases."  This is an index to judicially defined words and phrases found in cases.

Law Journals and Periodicals

Legal periodicals contain articles about law and law-related subjects.  These publications typically fall into one of the following categories: law reviews; specialized and scholarly journals; bar association journals; commercial journals in specialized fields; or legal newspapers. Many are available online via Westlaw and LexisNexis, but Heinonline has the most comprehensive archive.  The Law Library subscribes to many legal journals and periodicals.  Check the catalog for the call number to see them in our print collection.  You can also check the availability of a journal title (online or in print) by entering the journal title in the "Find Journals" search box on the Law Library website.

Legal Encyclopedias

Legal encyclopedias, unlike their counterparts in non-law libraries, are not written by legal scholars but by employees of the publishing company.  The Law Library offers two legal encyclopedias, both published by West:  American Jurisprudence 2d (Am Jur 2d) and Corpus Juris Secundum (CJS) in the Reference Area.  Use legal encyclopedias at the beginning of a research project to get an overview of the law.  Footnotes lead the researcher to cases, ALR Annotations and the West Topic and Key Numbers.

Am Jur 2d provides citations only to the cases the editors consider the best or most important while CJS strives to be comprehensive. Am Jur 2d is available on both Lexis and Westlaw. CJS articles tend to be longer and more detailed.  CJS is available on Westlaw.

Looseleaf Services

As their name implies, looseleaf publications are in large looseleaf binders.  Looseleaf publications cite relevant cases, state and federal statutes and regulations in a particular area of law.  They are in a looseleaf format to aid in frequent updating (daily, weekly, or monthly) as the law changes.  It pays in time savings to read the instructions in the front of the first volume since each looseleaf publication seems to have its own system.  Looseleafs can be organized by paragraph, section, or page number.  Some have companion volumes. Scan the index and table of contents.  Pay attention to the context. Large publishers of looseleaf services include Matthew Bender, BNA and CCH.  Look for these publishers on the spine of multi-volume sets throughout the collection.  Matthew Bender publications are available on LexisNexis.  The Law Library subscribes to several looseleaf publications in digital format.  Check the listing of databases for BNA or CCH.


Unique to law, each Restatement attempts to gather and synthesize case law on a topic, to organize it, and to present the "rules" distilled from the cases. These "rules" are the American Law Institute's attempt to provide "black letter law" for common law (case law or judge-made law) issues. Each restated subject area is divided into chapters, and further divided into topics and sections; the sections represent the "black letter law." Typical sections contain the rule of law, comments and illustrations used to clarify the rule, and major exceptions to the rule. Since 1976, case annotations appear in Appendix volumes specific to each restated subject area. The Appendix volumes supply case annotations to specific Restatement sections. They include a brief synopsis of the case and its holding, and are conveniently organized by jurisdiction. [Note that appendices are issued by date so there may be several volumes of appendices to check.] The appendices are updated with pocket parts. Restatements are shelved in the Reference Area and they are also available on Westlaw and LexisNexis.


Treatises, not to be confused with treaties, are book-length expositions on the law as it pertains to a particular subject. Treatises may be scholarly in nature or they may be geared toward a legal practitioner, such as a manual or handbook.  It may be a single volume or a multivolume set. Many are available electronically as well as in print. A topical list of legal treatises is available on Harvard Law Library's site. If you want to locate a treatise from the list in our print collection, merely search the catalog.

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