diction its refusal to take those actions was subject to judicial review, and (3) whether if reviewable its refusal was arbitrary, capricious, or an abuse of discretion. In reaching our conclusion that the Court of Appeals was wrong, however, we need not and do not address the thorny question of the FDA's jurisdiction. For us, this case turns on the important question of the extent to which determinations by the FDA not to exercise its enforcement authority over the use of drugs in interstate commerce may be judicially reviewed. That decision in turn involves the construction of two separate but necessarily interrelated statutes, the APA and the FDCA.
The APA's comprehensive provisions for judicial review of "agency actions" are contained in 5 U. S. C. §§ 701–706. Any person "adversely affected or aggrieved" by agency action, see § 702, including a "failure to act," is entitled to "judicial review thereof," as long as the action is a "final agency action for which there is no other adequate remedy in a court," see § 704. The standards to be applied on review are governed by the provisions of § 706. But before any review at all may be had, a party must first clear the hurdle of § 701(a). That section provides that the chapter on judicial review "applies, according to the provisions thereof, except to the extent that—(1) statutes preclude judicial review; or (2) agency action is committed to agency discretion by law." Petitioner urges that the decision of the FDA to refuse enforcement is an action "committed to agency discretion by law" under § 701(a)(2).
This Court has not had occasion to interpret this second exception in § 701(a) in any great detail. On its face, the section does not obviously lend itself to any particular construction; indeed, one might wonder what difference exists between § (a)(1) and § (a)(2). The former section seems easy in application; it requires construction of the substantive statute involved to determine whether Congress intended to preclude judicial review of certain decisions. That is the approach taken with respect to § (a)(1) in cases such as South-
