Document ID: ./input/supremecourt_opinions/opinions/17pdf/17-965_h315.pdf
Page Number: 51.0

Cite as:  585 U. S. ____ (2018) 

5 

THOMAS, J., concurring 

tered by a court of equity” had been reduced “into a regu-
lar science.”  3 W. Blackstone, Commentaries on the Laws 
of England 440–441 (1768) (Blackstone).  As early as 1768,
Blackstone  could  state  that  the  “remedy  a  suitor  is  enti-
tled to expect” could be determined “as readily and with as
much  precision,  in  a  court  of  equity  as  in  a  court  of  law.” 
Id.,  at  441.  Although  courts  of  equity  exercised  remedial 
“discretion,” that discretion allowed them to deny or tailor
a  remedy  despite  a  demonstrated  violation  of  a  right,  not 
to  expand  a  remedy  beyond  its  traditional  scope.    See  G. 
Keeton, An Introduction to Equity 117–118 (1938). 

In short, whether the authority comes from a statute or 
the  Constitution,  district  courts’  authority  to  provide 
equitable relief is meaningfully constrained.  This author-
ity  must  comply  with  longstanding  principles  of  equity 
that predate this country’s founding. 

II 

Universal injunctions do not seem to comply with those 
principles.  These  injunctions  are  a  recent  development,
emerging for the first time in the 1960s and dramatically 
increasing  in  popularity  only  very  recently.
  And  they
appear  to  conflict  with  several  traditional  rules  of  equity, 
as well as the original understanding of the judicial role.

Equity originated in England as a means for the Crown
to  dispense  justice  by  exercising  its  sovereign  authority.
See  Adams,  The  Origins  of  English  Equity,  16  Colum.
L. Rev.  87,  91  (1916).    Petitions  for  equitable  relief  were
referred  to  the  Chancellor,  who  oversaw  cases  in  equity.
See  1  S.  Symon’s,  Pomeroy’s,  Equity  Jurisprudence  §33
(5th  ed.  1941)  (Pomeroy);  G.  McDowell,  Equity  and  the 
Constitution  24  (1982).  The  Chancellor’s  equitable  juris-
diction was based on the “reserve of justice in the king.” F. 
Maitland, Equity 3 (2d ed. 1936); see also 1 Pomeroy §33,
at  38  (describing  the  Chancellor’s  equitable  authority  as
an  “extraordinary  jurisdiction—that  of  Grace—by  delega-