Document ID: ./input/supremecourt_opinions/opinions/20pdf/18-956_d18f.pdf
Page Number: 23.0

Cite as:  593 U. S. ____ (2021) 

19 

Opinion of the Court 

question whether those facts showed a “fair use” is a legal
question for judges to decide de novo. 

We agree with the Federal Circuit’s answer to this ques-
tion.  We have said, “[f]air use is a mixed question of law
and fact.”  Harper & Row, 471 U. S., at 560.  We have ex-
plained that a reviewing court should try to break such a
question into its separate factual and legal parts, reviewing 
each according to the appropriate legal standard.  But when 
a question can be reduced no further, we have added that 
“the standard of review for a mixed question all depends—
on whether answering it entails primarily legal or factual
work.”  U. S. Bank N. A. v. Village at Lakeridge, LLC, 583 
U. S. ___, ___(2018) (slip op., at 9). 

In this case, the ultimate “fair use” question primarily in-
volves legal work.  “Fair use” was originally a concept fash-
ioned by judges.  Folsom, 9 F. Cas., at 348.  Our cases still 
provide legal interpretations of the fair use provision.  And 
those  interpretations  provide  general  guidance  for  future 
cases.  See, e.g., Campbell, 510 U. S., at 592–593 (describing 
kinds  of  market  harms  that  are  not  the  concern  of  copy-
right); Harper & Row, 471 U. S., at 564 (“scope of fair use is
narrower  with  respect  to  unpublished  works”);  Sony,  464 
U. S., at 451 (wholesale copying aimed at creating a market 
substitute  is  presumptively  unfair).  This  type  of  work  is 
legal  work.  U. S.  Bank,  583  U. S.,  at  ___  (slip  op.,  at  8)
(“When applying the law involves developing auxiliary legal
principles for use in other cases[,] appellate courts should
typically review a decision de novo”).

Applying a legal “fair use” conclusion may, of course, in-
volve determination of subsidiary factual questions, such as
“whether there was harm to the actual or potential markets 
for the copyrighted work” or “how much of the copyrighted
work  was  copied.”    886  F. 3d,  at  1196;  see,  e.g.,  Peter  F. 
Gaito Architecture, LLC v. Simone Development Corp., 602 
F. 3d 57, 63 (CA2 2010) (noting that in an infringement suit 
“the question of substantial similarity typically presents an