Open a Supreme Court decision found by its citation and you will meet several documents bound together. Knowing which is which keeps you from quoting the wrong one.
Key idea
A decision may include a syllabus (a summary that is not part of the opinion), the opinion of the Court (the majority's reasoning, which states the law), concurring opinions (agreeing with the result, sometimes for different reasons), dissenting opinions and, when no reasoning wins a majority, a plurality opinion.
| Part | Who writes it | Is it law? |
|---|---|---|
| Syllabus | the Reporter of Decisions, for the reader's convenience | no: it "constitutes no part of the opinion of the Court" |
| Opinion of the Court | a justice for a majority (or "per curiam," unsigned, for the Court) | yes: its holding binds |
| Concurrence | a justice who joins the majority but adds views | no, but it may shape later readings |
| Concurrence in the judgment | a justice who agrees only with the result | no, though in split decisions it can matter |
| Dissent | a justice who disagrees with the result | no, but some dissents later become the majority view |
| Plurality opinion | the largest group when no reasoning has five votes | limited: lower courts look for the narrowest common ground |
Why it works
The Court speaks as a body only when a majority agrees on the reasoning. The syllabus comes first in the book, but every Supreme Court slip opinion carries the note that "the syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader," citing United States v. Detroit Timber & Lumber Co., 200 U.S. 321, 337 (1906). Separate opinions matter because they show the limits of a holding and the arguments for its future. Justice Robert Jackson's concurrence in Youngstown Sheet & Tube Co. v. Sawyer (1952) became the leading framework for presidential power, and Justice John Marshall Harlan's lone dissent in Plessy v. Ferguson (1896) is now far better known than the majority. When a decision has only a plurality, Marks v. United States (1977) tells lower courts to treat the position of the justices who concurred in the judgment on the narrowest grounds as the holding.
Worked example: Count the votes
Five justices join an opinion by Justice A. Justice B writes separately, "concurring in the judgment." Justices C, D and E dissent. Is A's opinion the opinion of the Court? What is the vote?
- Five justices joined A's reasoning: a majority of nine, so it is the opinion of the Court.
- B agrees with the result only, so the judgment has six votes.
- Three dissent.
Answer: Yes; the judgment is 6–3, and A's opinion is a majority opinion.
Worked example: A plurality
Four justices join an opinion reversing on ground X. Two justices concur in the judgment on ground Y. Three dissent. Is there an opinion of the Court?
- Six votes to reverse, so the judgment is reversed.
- But no single reasoning has five votes: four for X, two for Y.
- The four-justice opinion is a plurality opinion; lower courts look for the narrowest ground the majority shares.
Answer: No. The judgment is 6–3, announced in a plurality opinion.
Common mistake
Quoting the syllabus as the Court's words. In U.S. Reports the syllabus is prepared by the Reporter of Decisions and is not part of the opinion; headnotes added by publishers are not either. Check: is the passage under a justice's name (or "per curiam") after the words "opinion of the Court"? If not, find the matching passage in the opinion itself.
This is an educational course, not legal advice.