The Supreme Court’s decision in Pearson v. Callahan ended an eight-year experiment in the adjudication of qualified immunity claims. That experiment began with Saucier v. Katz, in which the Court held that lower courts must decide whether a government officer violated a plaintiff’s constitutional rights before addressing the question of whether the government officer was entitled to immunity. The Court’s rationale for requiring lower courts to first address the merits was the need to clarify constitutional law for the benefit of both government actors (who could then better conform their behavior to constitutional standards) and future plaintiffs (who could then overcome the defense of qualified immunity and recover damages for their injuries). But Pearson overturned Saucier’s mandate, holding that merits-first adjudication, while often appropriate, "should no longer be regarded as mandatory." The Court cited a number of reasons for its decision, including the detriment to judicial efficiency; the reality that principles articulated may be of little value, particularly if a higher court is about to pass on the same question or if the question involves state law; the difficulty of making law on uncertain facts when qualified immunity is asserted at the pleading stage; the concern that the government will be unable to appeal an unfavorable decision on the merits if it prevails on qualified immunity; and contravention of the longstanding principle of constitutional avoidance.