4 ELONIS v. UNITED STATES Opinion of ALITO, J. Staples v. United States, 511 U. S. 600, 605–606 (1994). For a similar reason, I agree with the Court that we should presume that an offense like that created by §875(c) requires more than negligence with respect to a critical element like the one at issue here. See ante, at 13– 14. As the Court states, “[w]hen interpreting federal criminal statutes that are silent on the required mental state, we read into the statute ‘only that mens rea which is necessary to separate wrongful conduct from “otherwise innocent conduct.” ’ ” Ante, at 12 (quoting Carter v. United States, 530 U. S. 255, 269 (2000)). Whether negligence is morally culpable is an interesting philosophical question, but the answer is at least sufficiently debatable to justify the presumption that a serious offense against the person that lacks any clear common-law counterpart should be presumed to require more. Once we have passed negligence, however, no further presumptions are defensible. In the hierarchy of mental states that may be required as a condition for criminal liability, the mens rea just above negligence is recklessness. Negligence requires only that the defendant “should [have] be[en] aware of a substantial and unjustifiable risk,” ALI, Model Penal Code §2.02(2)(d), p. 226 (1985), while recklessness exists “when a person disregards a risk of harm of which he is aware,” Farmer v. Brennan, 511 U. S. 825, 837 (1994); Model Penal Code §2.02(2)(c). And when Congress does not specify a mens rea in a criminal statute, we have no justification for inferring that anything more than recklessness is needed. It is quite unusual for us to interpret a statute to contain a requirement that is nowhere set out in the text. Once we have reached recklessness, we have gone as far as we can without stepping over the line that separates interpretation from amendment. There can be no real dispute that recklessness regarding a risk of serious harm is wrongful conduct. In a wide