A dazzling foray into scholastic thought by one of the foremost Thomists of the 20th century. Stylistically, the book is nearly flawless. Maritain writes with the technical precision of a philosopher and the elegance of a poet. The work ascends slowly through the various levels of knowledge, following the classical division of the speculative sciences (natural philosophy, mathematics, metaphysics) before culminating in the suprarational knowledge of theology and the infused wisdom of mystical experience. Perhaps my favorite section of the book was the chapter titled "Critical Realism", in which Maritain provides a thorough defense of the principles of Thomistic realism. The historical controversy surrounding such a defense, namely, the criticism leveled by Étienne Gilson that any defense of Thomistic realism is already a capitulation to idealist principles, is answered cogently by Maritain before he turns his analysis to the order of knowledge. He is careful to situate his defense of knowledge within the boundaries of metaphysics instead of following the modern division in which epistemology and metaphysics are separate sciences with their own distinct principles. In good Scholastic fashion, Maritain teaches that knowledge is primarily a mode of being in which the known comes to exist intentionally within the knower. Much more could be said in praise of this book, but the value of the work would be best promoted by Maritain's own pen, from the opening chapter entitled "The Majesty and Poverty of Metaphysics": "There is a sort of grace in the natural order presiding over the birth of a metaphysician just as there is over the birth of a poet. The latter thrusts his heart into things like a dart or rocket and, by divination, sees, within the very sensible itself and inseparable from it, the flash of a spiritual light in which a glimpse of God is revealed to him. The former turns away from the sensible, and through knowledge sees within the intelligible, detached from perishable things, this very spiritual light itself, captured in some conception. The metaphysician breathes an atmosphere of abstraction which is death for the artist. Imagination, the discontinuous, the unverifiable, in which the metaphysician perishes, is life itself to the artist. While both absorb rays that come down from creative Night, the artist finds nourishment in a bound intelligibility which is as multiform as God's reflections upon earth, the metaphysician finds it in a naked intelligibility that is as determined as the proper being of things. They are playing seesaw, each in turn rising up to the sky. Spectators make fun of their game; they sit upon solid ground." (p.2)