In Gonzales v. Oregon (2006) 546 U.S. 243, the court considered whether the Controlled Substances Act (CSA), by regulating controlled substances and making some substances available only pursuant to a prescription by a physician "issued for a legitimate medical purpose" (21 C.F.R. 1306.04(a) (2008)), permitted the federal government to effectively bar Oregon's doctors from prescribing drugs pursuant to Oregon's assisted suicide law by issuing a federal administrative rule (the Directive) that use of controlled substances to assist suicide is not a legitimate medical practice and dispensing or prescribing them for this purpose is unlawful under the CSA. The majority concluded the CSA's preemption clause showed Congress "explicitly contemplates a role for the States in regulating controlled substances" (Gonzales v. Oregon, at p. 251), including permitting the states latitude to continue their historic role of regulating medical practices. In dissent, Justice Scalia concluded title 21 United States Code section 903 was "embarrassingly inapplicable" to the majority's preemption analysis because the preemptive impact of section 903 reached only state laws that affirmatively mandated conduct violating federal laws. (Gonzales v. Oregon, supra, 546 U.S. at p. 289 (dis. opn. of Scalia, J.).) Thus, it appears Justice Scalia's interpretation suggests a state law is preempted by a federal "positive conflict" clause, like title, 21 United States Code section 903, only when the state law affirmatively requires acts violating the federal proscription. Justice Scalia explained that title 21 United States Code section 903 only "affirmatively prescribed federal pre-emption whenever state law creates a conflict. In any event, the Directive does not purport to pre-empt state law in any way, not even by conflict pre-emption--unless the Court is under the misimpression that some States require assisted suicide. The Directive merely interprets the CSA to prohibit, like countless other federal criminal provisions, conduct that happens not to be forbidden under state law (or at least the law of the State of Oregon)." (Gonzales v. Oregon, supra, 546 U.S. at pp. 289-290 (dis. opn. of Scalia, J.).)