Reference · 129 entries · 10 subjects

Doctrines, and how old the reasoning is

Every entry answers four questions: what problem the doctrine solves, what fact pattern signals it, which decision anchors it, and what limits sit on that decision today. The age column is the point of the exercise — you are learning rules written by people who are mostly dead, and it is worth knowing how long ago.

Age is chronology, not authority. Age = 2026 minus the decision year, and it measures the age of the identified case’s reasoning, not the birthday of the doctrine. A modern case applying an ancient principle does not make the principle modern. An older opinion can be binding and a newer one can be displaced. Nine entries rest on model-code or statutory text with no single decision, and carry no age at all.
When the anchor reasoning was written

Fifty-nine entries anchor to reasoning from the second half of the twentieth century and eighteen to this century, but the spine of the first-year curriculum sits further back: forty-three anchors predate 1950, and four predate the American Civil War. That is not a criticism of the doctrine. It is a fact about whose circumstances were in the room when the language was written, and it is worth holding while you memorise it.

How to read the anchors. A holding must be read against its facts, its court, and its procedural posture. State decisions do not control other states. English cases are historical anchors or analogues, not U.S. authority. UCC citations reproduce model text — the applicable state enactment is what governs. Use the anchor to learn the reasoning, then check the governing jurisdiction and subsequent treatment before relying on it.

The entries

Subject
Era
Order

Distinctions that prevent common mistakes

Fourteen pairs that get conflated, and the question each one actually answers. These are the errors that survive into exam answers, because both halves feel familiar on their own.

Reading glossary

Reading aids for the tables above, not substitute elements of any claim. Where a term carries several legal meanings, this is the one used here.