Ignatius Eschmann, O.P. (1898-1968) was a most distinguished interpreter of Saint Thomas Aquinas, if we take 'interpreter' in the double sense of one who knows what Thomas meant and who brings to that interpretation what our century has made available. Two sides of Eschmann are clear: he was a controversialist who, after his prison year, was hésitant to publish; he was also a constructive thinker, unwilling to substitute commentators, no matter how classical, for the Master. Both sides are patent in this book. Saint Thomas redivivus would surely recognize in these lectures the seeds he had sown seven centuries earlier.