Types of Secondary Sources
Secondary sources provide commentary, analysis, and interpretation of primary law (constitutions, statutes, court decisions). They don't create law themselves, but they help you understand it. Think of them as the guides that walk you alongside the primary sources, pointing out what matters and why.
For legal research, secondary sources are often where you should start. They give you the lay of the land before you dive into case law and statutes, and they can point you toward the most relevant primary authorities.
Law Reviews and Journals
Law reviews and journals are scholarly publications produced by law schools and professional organizations. They contain in-depth articles on specific legal topics written by professors, practitioners, and even law students (through student notes and comments).
- Often include critical analysis of recent court decisions and emerging legal trends
- Peer-reviewed or student-edited, which helps maintain quality and rigor
- Particularly useful when you're researching a cutting-edge or unsettled area of law, since scholars often publish on these topics before courts have fully addressed them
- Can be highly specialized, with journals devoted to areas like environmental law, intellectual property, or civil rights
Legal Encyclopedias
Legal encyclopedias are broad reference works that cover virtually every area of law, organized alphabetically by topic. They're your best friend when you're starting research on an unfamiliar subject because they give you a concise overview and then point you to relevant primary sources through footnotes.
- Provide summaries of legal principles with citations to supporting cases and statutes
- Two major national encyclopedias: American Jurisprudence (Am. Jur.) and Corpus Juris Secundum (C.J.S.)
- Not the place for deep analysis, but excellent for getting oriented quickly
- Many states also have their own encyclopedias (e.g., California Jurisprudence, Texas Jurisprudence)
Treatises and Hornbooks
Treatises are in-depth, authoritative texts on specific areas of law written by recognized experts. A good treatise covers the historical development, current state, and open questions within its subject. Hornbooks are more concise versions, often aimed at law students preparing for exams.
- Both include extensive citations to primary law and other secondary sources
- Treatises by well-known authors can carry significant persuasive weight with courts. For example, Prosser on Torts and Corbin on Contracts are frequently cited in judicial opinions.
- Valuable for understanding complex legal concepts and identifying the key cases or statutes in a field
Restatements of Law
Restatements are produced by the American Law Institute (ALI), a group of prominent judges, lawyers, and professors. Their goal is to clarify and organize common law principles into clear, concise statements of legal rules.
- Organized by subject area: Restatement (Second) of Contracts, Restatement (Third) of Torts, Restatement of Property, etc.
- Each rule includes official comments and illustrations that show how the rule applies in practice
- Widely respected and frequently cited by courts, though they are not binding authority
- Particularly useful when case law across jurisdictions is inconsistent, since restatements attempt to synthesize the majority approach
Legal Dictionaries
Legal dictionaries define legal terms, phrases, and concepts with precision that general dictionaries can't match. When you encounter unfamiliar terminology in a case or statute, a legal dictionary is the quickest way to get a reliable definition.
- Often include etymologies and historical usage of terms
- Black's Law Dictionary is the most widely used and frequently cited by courts
- Ballentine's Law Dictionary is another well-known option
- Useful not just for studying but also for legal writing, where precise word choice matters
Authority of Secondary Sources
Secondary sources hold persuasive rather than binding authority. Understanding this distinction, and knowing which secondary sources carry more weight, is critical for effective legal writing.
Persuasive vs. Binding Authority
Binding authority consists of primary sources that a court must follow: constitutions, statutes within that jurisdiction, and decisions from higher courts in the same chain. Secondary sources are never binding. Instead, they serve as persuasive authority, meaning courts may consider them but aren't obligated to follow them.
That said, not all persuasive authority is created equal. A restatement provision or a treatise by a leading scholar carries far more weight than a student note in a lesser-known journal. Courts sometimes adopt reasoning directly from highly regarded secondary sources, especially in areas where primary law is sparse or unsettled.
Weight in Different Courts
- Federal courts may give more weight to federal-focused secondary sources
- State courts often rely more heavily on state-specific materials
- Appellate courts tend to be more receptive to academic articles and treatises than trial courts, since appellate decisions often address broader legal questions
- Specialized courts (tax, bankruptcy) frequently value subject-specific secondary sources
Factors Affecting Influence
Several factors determine how much weight a court or reader will give a secondary source:
- Author reputation and credentials in the relevant field
- Recency of publication and relevance to current legal issues
- Depth of analysis and quality of supporting citations
- Frequency of citation by courts and other authorities
- Alignment with established legal principles and precedents
- Clarity and persuasiveness of the source's reasoning
Functions of Secondary Sources
Secondary sources serve several distinct purposes in legal research. Knowing why you're consulting a secondary source helps you pick the right type.
Explaining Primary Law
Secondary sources translate complex statutes and case law into more accessible language. They break down the key elements of legal rules, highlight requirements that might not be obvious from reading the primary source alone, and illustrate how principles apply through examples and hypotheticals. This is especially helpful when a statute is dense or when a court opinion is long and hard to parse.
Providing Historical Context
Legal rules don't appear out of nowhere. Secondary sources trace how doctrines developed over time, explain the rationale behind changes in the law, and describe the social, political, and economic forces that shaped legal evolution. Understanding this history helps you grasp why the law is what it is today, which strengthens your analysis.
Analyzing Legal Trends
Secondary sources identify emerging patterns and shifts in legal thought across jurisdictions. They compare different approaches to similar issues, evaluate the impact of recent legislative changes or court decisions, and highlight inconsistencies in how legal principles are applied. This kind of cross-jurisdictional analysis is something you'd struggle to do efficiently on your own.
Suggesting Future Developments
Scholars and practitioners use secondary sources to propose reforms, predict likely outcomes of pending cases, and identify areas of law that need clarification. These forward-looking analyses can be valuable when you're crafting policy arguments or trying to anticipate how a court might rule on a novel issue.
Research Strategies
Knowing how to use secondary sources effectively is just as important as knowing what they are.
When to Use Secondary Sources
- At the start of research to gain an overview of an unfamiliar topic
- When primary sources are ambiguous or conflicting
- To identify relevant primary sources and key cases on a particular issue
- When you need historical context or policy arguments
- To supplement your analysis in complex or evolving areas of law
Finding Relevant Secondary Sources
- Start with legal research databases like Westlaw, LexisNexis, or HeinOnline
- Consult your law library's catalog and subject-specific research guides
- Use citation indexes to track influential articles and treatises
- Follow the footnotes and bibliographies of sources you've already found, since good sources lead to other good sources
- Ask a law librarian for guidance on specialized or hard-to-find materials
Evaluating Source Reliability
Before relying on a secondary source, assess it critically:
- What are the author's credentials and expertise?
- When was it published? Is the information still current?
- What is the reputation of the publisher or journal?
- How thoroughly does it cite primary sources?
- Has it been cited by courts or other authoritative works?
Citing Secondary Sources
- Follow the citation format specified in The Bluebook (or ALWD Citation Manual, depending on your program)
- Include full bibliographic information for books, articles, and online sources
- Properly attribute all quotes, paraphrases, and borrowed ideas
- Use appropriate introductory signals (see, cf., but see) to show the relationship between the source and your argument
- Stay consistent in citation style throughout your document
Key Secondary Sources
Familiarity with the most widely used secondary sources will make your research more efficient.
American Law Reports (ALR)
ALR annotations are detailed articles on specific legal issues that collect and analyze relevant cases from multiple jurisdictions. If you have a narrow legal question and want to see how different courts have handled it, ALR is often the best place to look.
- Organized by topic, with in-depth treatment of focused legal questions
- Annotations summarize and compare cases across jurisdictions
- Regularly updated to reflect new developments
- Useful for finding analogous cases to support your argument
American Jurisprudence (Am. Jur.)
Am. Jur. is a comprehensive legal encyclopedia covering all areas of American law. It's organized alphabetically by topic and provides concise statements of legal principles with citations to supporting cases and statutes. It also includes practical aids like checklists, forms, and procedural guides, making it useful beyond pure research.
Corpus Juris Secundum (C.J.S.)
C.J.S. is the other major national legal encyclopedia, covering both state and federal law. Compared to Am. Jur., C.J.S. tends to include more extensive case citations and provides more historical background on the development of legal doctrines. It also features cross-references to related topics within the encyclopedia.
State-Specific Secondary Sources
- Practice guides tailored to individual state laws and procedures
- State legal encyclopedias (e.g., California Jurisprudence, Texas Jurisprudence)
- Annotated state statutes with commentary and case summaries
- State bar publications and continuing legal education (CLE) materials
- Local law review articles focusing on state-specific issues
Online vs. Print Sources
Legal research has shifted heavily toward digital tools, but print resources still have a role. Understanding the strengths of each format helps you research more effectively.
Digital Databases
- Offer vast, searchable collections of primary and secondary sources
- Provide advanced search features, including Boolean operators and natural language searching
- Allow easy updating and tracking of new legal developments
- Enable quick cross-referencing and hyperlinking between related sources
- Facilitate efficient citation checking through tools like KeyCite (Westlaw) and Shepard's (LexisNexis)
Traditional Library Resources
- Provide access to historical materials that may not be digitized
- Allow for browsing, which can lead to discovering related materials you wouldn't have found through keyword searches
- Offer a focused environment for in-depth study
- Ensure access to sources that may be restricted or unavailable online
Advantages and Limitations
- Online sources offer speed and convenience but often require expensive subscriptions
- Print sources provide stability but are harder to keep current
- Digital tools enable powerful searching but can lead to information overload if you don't refine your queries
- Libraries offer expert assistance from librarians, which is an underused resource for many students
Ethical Considerations
Using secondary sources comes with ethical responsibilities that apply in both academic and professional settings.
Proper Attribution
Always cite your sources for ideas, quotes, and paraphrases. Follow your citation guide's rules to accurately represent where material came from. Plagiarism in legal writing can result in academic discipline, bar admission problems, and professional sanctions. Provide enough information for your reader to locate and verify every cited source.
Avoiding Overreliance
Secondary sources are starting points, not endpoints. Always verify what a secondary source tells you by checking the primary law it references. Develop your own analysis rather than simply restating what a treatise or article concluded. This is especially important in rapidly changing areas of law, where secondary sources may be outdated by the time you read them.
Balancing Secondary and Primary Sources
- Use secondary sources to guide your research, but build your legal arguments on primary law
- Incorporate a mix of secondary sources to provide diverse perspectives
- Make sure secondary sources enhance your analysis of primary law rather than replace it
- Be cautious of outdated secondary sources that may not reflect current legal standards
- Consider the appropriate ratio of primary to secondary citations based on the type of document you're writing. A court brief should lean heavily on primary law, while a law review article might cite secondary sources more freely.
Secondary Sources in Legal Writing
Knowing how to integrate secondary sources into your writing is a skill you'll use throughout law school and practice.
Incorporating into Legal Arguments
- Use secondary sources to provide context and background for the legal issue
- Cite respected authorities to support your interpretation of ambiguous statutes or case law
- Reference scholarly articles to introduce novel legal theories or arguments
- Incorporate historical analyses to show how a doctrine has evolved
- Draw on secondary sources to demonstrate the broader implications of a legal principle
Strengthening Persuasive Writing
- Cite respected scholars or practitioners to lend credibility to your position
- Reference empirical studies or statistical data from secondary sources to support factual claims
- Use secondary sources to anticipate and address counterarguments before the other side raises them
- Incorporate analogies or examples from treatises and articles to clarify complex concepts for the reader
Limitations in Formal Documents
Secondary sources should be used carefully in court filings and formal legal documents. Courts expect arguments grounded in primary law. Overusing secondary sources in a brief can signal that you couldn't find strong primary authority to support your position. Use secondary sources to supplement and explain, but make sure your core arguments rest on binding or directly relevant primary law.