Equity Does What It Does--For the Parties

In reading an old treatise's discussion of preliminary injunctions, I came across this quotation:

An interlocutory injunction is merely provisional in its nature, and does not conclude a right, while the perpetual injunction is a final decree upon full hearing, and concludes all parties in interest.

Thomas Carl Spelling, Treatise on Extraordinary Relief in Equity and at Law § 31, at 42 (1893). It's reminder of the principle that equitable decrees were conclusive for the parties, not for the world at large. That's why the old equity cases and treatises spend so much time on figuring out who the proper parties are and whether they've all been joined. Because the scope of the parties, including those represented by the parties, will be the scope of the court's decree.

For contemporary implications, of course, see Multiple Chancellors.