Dakin Matthews is an acclaimed actor, whose relationship with the stage and lyrical performance has made him keenly aware of the splendor and meaningfulness of Thomas Aquinas' often overlooked verse. The 'songs of Aquinas' are treasuries of theological wisdom but also serve to stir the mind to participate in prayer with as much zeal as the heart and mouth. Matthews offers an introduction to Aquinas and his main objectives for writing, and then relates the more serious theological treatises to the style and purposes of his verse. It is a full but never overwhelming immersion in Thomistic thought, as well as a brilliant guide to Medieval Latin and the art of translation.       Matthews' particular attention is given to "Lauda Sion," and he breaks it down, verse by verse, providing an analysis of the Latin text and commentary on its poetic structure, but also illuminates the doctrinal references to Aquinas' other scholarly works and Scripture. His approach is both technical and intermittently personal, and as such this book might serve as a two-week source of daily meditations.               The Alleluias of the Mind  is a wonderful contribution to the body of Thomistic commentary and will appear before the close of the 750th anniversary of the death of Thomas Aquinas. It is also a wonderful complement to the year devoted to Eucharistic revival in the American Catholic Church.