Juan de Valdés belongs to a sizable group of sixteenth-century religious thinkers whose importance was so overshadowed by the great reformers that they have never had their historical due. That more than 400 years after Valdés’ death it should require so painstaking a detective and interpretive job as Dr. Nieto’s to clear this interesting Spanish scholar and theologian of accumulated myths and lay bare the true source and nature of his doctrines is a comment on the tendency of historical opinion to attribute to major figures a uniqueness they never possessed. To be sure, the Inquisition had done its best to destroy Valdés’ reputation by suppressing his works and maligning his name. Dr. Nieto must therefore begin with a careful reconstruetion of Valdes’ works and letters in their chronological and thematic relationship. Next comes an investigation of his Spanish background. This is composed of the Alumbrados, of a number of mystics, and— most importantly—of Pedro de Alcaraz, whose doctrine of the dexamiento to the love of God (“communion with God, non-mystical and without substantial union of the soul, but in ‘conformation’ with the will of God”) was the source of Valdés’ own knowledge of sin and grace. The first fruit of this knowledge was the Diálogo de doctrina cristiana of 1527, the only book Valdés published in his life time. Analysis of this work reveals a radical theocentrism from the vantage point of which Valdés subjects the institutional Church and its teachings to searching criticism—a criticism which proved catching among Valdés’ acquaintances in Naples and Viterbo. Neither direct Protestant influence nor a generalized Erasmianism accounts for this position, which the author traces entirely to Spanish sources, notably Alcaraz.

So far, Dr. Nieto’s operation has been largely ground clearing. In the second part of his book he advances to a long and cautious theological dissection of Valdés’ writings, particularly of his religious epistemology. This, it turns out, is securely founded on “experience” which—in religious knowledge—means an intense feeling of the true life in Christ, or “incorporation in Christ,” the “inward effects of the Holy Spirit.” Faith follows from this experience, but only in man’s awareness of it. As a divine gift, faith contains the ground of religious experience, not vice versa. Experience makes faith personal and vital. It translates itself into thought (the formulation and acceptance of doctrines) and action.

All this is set out patiently and, perhaps, at excessive length (Dr. Nieto’s prose tends to inflation, and he is not helped by an extraordinary number of “typos” in the text). But while to the non-theologian Valdés’ doctrines seem close enough to Luther’s to obscure differences, the logical and—above all—psychological approaches to these doctrines are sufficiently distinct to make this exhaustive exposition of Valdés’ thought a welcome addition to the literature on the Reformation of the sixteenth century.