Do Suits in Equity Imply a Cause of Action for Damages?

This morning's decision in DeVillier v. Texas, written by Justice Thomas for a unanimous Court, has this meticulously careful description of the relationship between law, equity, and causes of action, with a citation to my colleague A.J. Bellia's excellent work with Brad Clark (emphasis added):

The cases that DeVillier cites do not directly confront whether the Takings Clause provides a cause of action for just compensation. First English itself proceeded under a state-law cause of action. Id., at 313–314, n. 8. DeVillier also points to several takings cases where property owners sought injunctions to prevent the Government from interfering with their property rights, such as by obtaining easements or imposing zoning regulations. See Dohany v. Rogers, 281 U. S. 362, 364 (1930); Delaware, L. & W. R. Co. v. Morristown, 276 U. S. 182, 188 (1928); Village of Euclid v. Ambler Realty Co., 272 U. S. 365, 384 (1926); Cuyahoga River Power Co. v. Akron, 240 U. S. 462, 463 (1916); Norwood v. Baker, 172 U. S. 269, 276 (1898). Because none of those cases relied on §1983 for a cause of action, he reasons that those cases must have proceeded directly under the Constitution. But, the mere fact that the Takings Clause provided the substantive rule of decision for the equitable claims in those cases does not establish that it creates a cause of action for damages, a remedy that is legal, not equitable, in nature.2 That said, the absence of a case relying on the Takings Clause for a cause of action does not by itself prove there is no cause of action. It demonstrates only that constitutional concerns do not arise when property owners have other ways to seek just compensation. Our precedents do not cleanly answer the question whether a plaintiff has a cause of action arising directly under the Takings Clause.

FN 2: The significance of DeVillier's equitable cases is further obscured by fundamental changes to the law of equity that postdate those decisions. Compare Fed. Rule Civ. Proc. 2 with A. Bellia & B. Clark, The Original Source of the Cause of Action in Federal Courts, 101 Va. L. Rev. 609, 653 (2015).

This is very well done. And though terse, it suggests a much better path than Harlan's concurrence in Bivens, which addresses and gets exactly wrong the relationship between law and equity and a cause of action.

In the forthcoming edition of Ames, Chafee, and Re on Remedies, I included a note after Bivens that addresses the argument that since there is a basis for a suit in equity, there must therefore be a cause of action for damages. The short answer: no. Here's the note:

NOTE ON EQUITY AND GRANTS OF GENERAL JURISDICTION
Justice Harlan presumes that if a grant of general jurisdiction is enough
for judges to grant equitable relief, it should also be enough for judges to
allow a cause of action for damages. One important distinction, though, is
that equity does not traditionally have causes of action. See generally
Samuel L. Bray & Paul B. Miller, Getting into Equity, 97 Notre Dame L. Rev.
1763 (2022). It would be unsurprising, therefore, for a statute to authorize a
court to give equitable relief with a grant of general jurisdiction, while for legal relief statutes tend either to create a new cause of action or to codify a
common law one (with or without alteration).