There are few legal doctrines as debated and dissected as the direct effect of EU law. Even in the light of this, Daniele Gallo’s re-statement of the sources, scholarship and case law surrounding such doctrine deserves praise. Direct Effect in EU Law offers the first comprehensive monograph in decades devoted exclusively to the evolution, logic, and contemporary redefinition of direct effect, a foundational yet persistently contested element of the EU’s constitutional identity. Gallo’s central claim is that direct effect has never been a static judicial technique but a constitutional principle whose transformative capacity has in more recent years gradually been obscured by formalism and by the Court of Justice’s turn toward what he calls judicial argumentative minimalism.