It would also be interesting if there were lists of this nature at the state level too.

1 Answer 1


Short Answer

Is there a list of doctrines and rationale in American common law that isn't based on codified laws and constitutional rules?


There is really nothing so compact as a mere list.

Long Answer

West Key Numbers

Maybe the closest thing to a mere list of the topics and doctrines that are out there, without any of the substantive content of those topics and doctrines would be the West Key Number system which just lists the topics into which the legal publishing firm that operates under the brand name "West" organizes its headnotes in its legal digests of legal holdings of reported and selected unreported legal case opinions. West pays a small army of lawyers to prepare headnotes tied to the West key system by hand for every such case reported by West in its case reporters. But the West key system service that has started to become obsolete as more sophisticated search tools for the text in court cases has been developed with of the best search tools being specific to its online pay per view Westlaw legal resource search engine. A webpage at Stanford University explains how this works:

The West Key Number System is a classification system of U.S. law that indexes cases into over 400 topics and more than 98,000 legal issues. Westlaw assigns a topic and key number to each legal issue within a case. The West Key Number System allows you to efficiently find other cases addressing your legal issue in any jurisdiction because all federal and state cases included in the system are organized using the same topics and by the same points of law.

Using the West Key Number System is particularly useful when you have identified a relevant case and would like to find additional cases addressing a certain point of law or legal issue from other jurisdictions.

A key number consists of a topic number, followed by a number to identify the issue within that topic. For instance, 349k28 is referring to the topic of Searches and Seizures (349) and the issue of abandoned, surrendered, or disclaimed items (k28).

This list of 98,000 key numbers, however, is really a great oversimplification because the vast majority of key numbers of the West system have many numbered subtopics. At the finest grained level, the West key number system probably has something on the order of a million sub-topics (although many of those topics involve areas of law that are rooted in statutes or constitutions or treaties).

A mere table of contents, at the key number level (not the subtopic level), of the entire West Key Number system, is more than thousand pages long. Even a top level list of the 400 West top level topics would probably take more space that the Law.SE system allows in a single question or answer.

Relatively comprehensive compendiums of common law doctrines

You could buy full set of legal treatises, like the West digests, or a full set of law school textbooks, or famed subject-matter treaties in particular areas of the law and these would hit most of the high points, but there really isn't any truly comprehensive and compact list.

Perhaps the closest thing out there would be a full set of the Restatements of Law which are attempts to quasi-codify the majority or "better" rules of the common law in particular subject areas, which are drafted by a committee specialist law professors and legal experts in a legal subject led by a law professor chair of the committee called a "reporter" who writes most of the first draft, under a process sponsored by an affiliated with, but that is not formally a part of, the American Bar Association. There are Restatement of the law of torts, contracts, property, trusts, and judgments, for example.

Historically, there were other legal encyclopedias like Corpus Juris, in book form arranged by subject matter and running maybe 25-40 volumes, and there were also periodical publications like American Jurisprudence and ALR that did several fairly comprehensive summarizes of law on very specific topics each month. But almost all of these are now either defunct entirely, or have seen their share of the legal research resources market plummet to almost nothing.

The shortest comprehensive treatments would be encyclopedia length (e.g. perhaps 26 full sized volumes), and the shortest summary treatments would be perhaps 6-8 books long (e.g., a full set of law school student outlines for the main law school class common law topics, or a full set of bar exam review outlines covering the non-statutory subjects on the bar exam). You could only scratch the surface in a single book length treatment, like a single business law course textbook.

Fragments of the common law in the most commonly litigated issues in the most commonly litigated areas where there is a right to a jury trial, however, can be found in pattern jury instructions for civil cases for a particular state, which run to one or two full book length volumes in most cases. But a full set of civil pattern jury instructions omits lots common law subjects that are handled by judges alone in procedural matters and equity jurisprudence, and it omits common law subjects where even though there is a right to a jury trial the subject is less frequently litigated. You could find almost all of the law relevant to routine, plain vanilla breach of contract cases, automobile accident cases, and slip and fall cases in pattern civil jury instructions, but would find little about property law or about less common kinds of contract and tort claims and defenses.

One of the reasons that most of the world other than long term British colonies use the civil law systems originating in Continental Europe, rather than the common law legal system, is that civil law systems compile their core legal doctrines of "private law" (i.e. the law governing dealings that don't involve the government) in one civil code, sometimes supplemented by one or two other codifications, like a commercial code, rather than from a sprawling, ill-defined, and unwieldy collection of appellate court precedents spanning centuries.

State common law

It would also be interesting if there were lists of this nature at the state level too.

This is an upside down way to think about American common law.

American common law is, overwhelmingly and predominantly, state law (including the local law of self-governing territories of the U.S. like the Virgin Islands and the District of Columbia).

Common law rules differ from state to state and it isn't uncommon for their to be 2-6 different common law rules adopted in different jurisdictions on the same subject (e.g. an attorney's liability to a third-party as a third-party beneficiary of an attorney-client relationship). See also a related Law.SE answer to the question: What are the most prominent differences among the common law systems of the different states in the U.S.A.? to get a somewhat idiosyncratic list of the differences that can give you some of the flavor of how this plays out in practice.

For the most part, common law at the state level in the United States has a common origin in colonial era English common law, and there was lots of interstate borrowing of common law decisions up through roughly the 1920s (producing doctrines like the "American Rule" regarding attorney fee shifting in litigation). But since then, common law has developed largely on a state by state level with much more modest reference as persuasive authority to common law decisions of other U.S. jurisdictions.

In the late 1700s, and well into the 1800s, the prevailing view was that the common law was an organic form of "natural law" that was discovered rather than created by judges and was universal.

But the modern "positivist" view is that the common law is created by judges from a particular jurisdiction and is not "natural" or "universal". The modern positivist legal theory position, which is dominant, is that instead, the common law represents an intersubjective consensus about moral and ethical norms that are a product of the culture that they are created in. This culture is a set of cultural norms that both influences judges and is influenced and shaped by judges.

Federal common law

There is some federal common law separate from any constitutional or statutory foundation, but the scope of the federal common law is tiny and obscure relative to the scope of state common law.

Federal common law is primarily found in the subject areas of admiralty law, writ practice, evidentiary privileges in federal court litigation, customary international law, the law pertinent to disputes between states over water rights, some parts of choice of law doctrines, certain immunities from lawsuits, and employee benefits law in circumstances where the broadly pre-emptive ERISA statute does not apply.

More generally, in the United States, most law, both civil and criminal and statutory, arises at the state level, and federal law mostly supplements state law in specific subject-areas that are a product of the language of the U.S. constitution and the way that legislation and treaties and U.S. Constitutional interpretation have evolved over time.

State common law issues tried in federal courts

Federal courts only have jurisdiction over ordinary common law topics in diversity cases (i.e. large dollar lawsuits between people from different states or countries where a federal court forum was chosen by one of the parties), and in cases where state law claims are included as a part of a case which also has federal law claims (which are overwhelmingly statutory or constitutional in nature).

In these cases, federal courts generally apply the substantive state common law that a state court of general jurisdiction in the state where the federal court is located would apply, looking to state case law as controlling precedents. This is called the Erie doctrine after the U.S. Supreme Court case that clarified how this works.

On questions of first impression where there is no state case law on point, federal courts ask the state's supreme court how it would rule on the topic in a process call presenting a "certified question" to the state supreme court.

  • 1
    Note on that last point: that is indeed what is supposed to happen but I have encountered plenty of complains about federal courts in fact not doing so. Particularly where there are intermediate (or even district) state court opinions on the topic but nothing from the state supreme court. Commented Mar 23 at 22:58

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