The essays in this volume offer a critique of <i>From Unity to Pluralism: The Internal Evolution of Thomism</i> by Gerald McCool, SJ. Twelve philosophers in this collection analyse key aspects of McCool's interpretation of Aquinas, which stands opposed to the motivating ideals found in <i>One Hundred Years of Thomism: Aeterni Patris and Afterwards</i>, a symposium published in 1981 to celebrate the centenary of Pope Leo XIII's encyclical <i>Aeterni Patris</i>.