Our author is vigorous and clear in thought and expression. Extremely liberal in his views, much of his writing has been polemic. In argument he is shrewd and incisive; in criticism, candid but unsparing. His _Principios criticos_ is a scathing arraignment of the government of New Spain under the viceroys. His _Filosofía_ is a part of the same discussion. It forms a large octavo volume. It begins with presenting two Latin documents of the eighteenth century, programs of public _actos_, given at the _Seminario_ and the _Colegio de Santo Tomás_ in Guadalajara. These serve as the basis for a severe criticism of the philosophical thought and teaching in Spain and New Spain during the vice-regal period. Testimonies are cited from many authors and Rivera’s comments upon and inferences from these are strong and original. In the course of the book he summarizes the scientific work really done--and there was some--in Mexico during the seventeenth and eighteenth centuries. He sums up his argument in eleven corollaries. Our selections are taken from the _Filosofía en Nueva España_ and from a curious dialogue regarding the teaching of Indian languages. On February 28, 1902, after many years of absence, Agustin Rivera was in Guadalajara; his completion of seventy-eight years of life was there celebrated by a large circle of his friends, old students, admirers, and readers, most brilliantly. In October, 1901, a proposition, that the national government should pension the faithful and fearless old man, was unanimously carried by the one hundred and twenty-five votes in the House of Deputies in the City of Mexico. It is pleasant to see these acts of public recognition of the value of a long life usefully spent. BACKWARDNESS OF MEXICO IN VICEROYAL TIMES. My lack of pecuniary resources does not allow me to give greater bulk to this book by translating Document I. from Latin into Spanish; but those who know the Latin language and philosophy will observe that in the Department of Physics in the College of Santo Tomás in Guadalajara were taught _the first cause_, _the properties of secondary causes_, supernatural operations, the sacrament of the Lord’s Supper, eternity--everything, in fact, save physics. Neither the word _heat_, nor the word _light_, is met with once in the program. The program cited, further accentuates ignorance of modern logic and modern metaphysics. Such was the teaching of philosophy by the Jesuits in the schools of New Spain, until the end of their instruction and existence in this country, since the public _acto_, in the College of Santo Tomás, took place in 1764, and three years later they were expelled (June 25, 1767). History proves that the Jesuits were at the front in teaching in the colleges of New Spain, and if _they_ taught such things, what could those teach who were in the rear?