Document ID: ./input/supremecourt_opinions/opinions/21pdf/20-1410_1an2.pdf
Page Number: 24.0

4 

XIULU RUAN v. UNITED STATES 

ALITO, J., concurring
ALITO, J., concurring in judgment 

son knowingly or intentionally . . . to manufacture, distrib-
ute, or dispense, or possess with intent to manufacture, dis-
tribute, or dispense, . . . a controlled substance.”  According 
to the Court’s reasoning, the terms “knowingly or intention-
ally” in §841(a)(1) apply to the “except as authorized” pro-
viso at the beginning of the provision.  But it is hard to see 
how this could be true. 

As  a  matter  of  elementary  syntax,  the  adverbs  “know-
ingly” and “intentionally” are most naturally understood to 
modify  the  verbs  that  follow,  i.e.,  “manufacture,”  “distrib-
ute,”  etc.,  and  not  the  introductory  phrase  “except  as  au-
thorized.”  That phrase, in turn, clearly modifies the term
“unlawful.” 

The Court does not suggest otherwise. It does not claim 
that “knowingly or “intentionally” modifies the introductory 
proviso in a grammatical sense.  (If it did, the introductory 
phrase would clearly be an element, and for reasons that I 
will  explain,  infra,  at  5–6,  21  U. S. C.  §885  unmistakably 
rules that out.)  Instead, the Court pointedly uses different
terminology.  It repeatedly says that the phrase “knowingly
or intentionally” “applies” to the introductory phrase, ante, 
at 2, 4, 6, 9, 15 (emphasis added).  And it reaches this con-
clusion  based  on  grounds  that  have  nothing  to  do  with 
grammar or syntax.

Specifically, the Court relies on a substantive canon of in-
terpretation—the  mens  rea  canon.    Under  this  canon,  the 
Court interprets criminal statutes to require a mens rea for 
each element of an offense “even where ‘the most grammat-
ical reading of the statute’ does not support” that interpre-
tation.  Rehaif,  588  U. S.,  at  ___  (slip  op.,  at  6)  (quoting 
United  States  v.  X-Citement  Video,  Inc.,  513  U. S.  64,  70 
(1994)).*  But until today, this canon has been applied only 
—————— 

*Why  we  have  held  that  the  mens  rea  canon  allows  courts  to  ignore 
obvious textual evidence of congressional intent is not obvious.  In our 
constitutional  system,  it  is  Congress  that  has  the  power  to  define  the 
elements of criminal offenses, not the federal courts.  Liparota v. United