Such being the general conditions, what was the actual situation? In practice freedom was general, save in philosophy and theology. In law, in medicine, in grammar and mathematics, men were normally free to lecture and dispute as they would. As there was no social problem in the modern sense and no teaching of the social sciences as such, a fruitful source of difficulty was absent. So far as I know, no mediaeval professor was condemned for preaching free trade or free silver or socialism or non-resistance. Moreover, while individual treatises might be publicly burnt, as in the later Roman Empire, there was no organized censorship of books before the sixteenth century. Now as to philosophy and theology. The trouble lies of course with theology, for philosophy was free save when it touched theological questions. But then, philosophy is very apt to touch theological questions, and all through the twelfth and thirteenth centuries there was an intermittent fight between Christian theology and pagan philosophy as represented by the works of Aristotle. It began with Abelard when he tried to apply his logical method of inquiry to theology, and it went on when his contemporary, Gilbert de la Porrée, directed still more of the Aristotelian logic toward theological speculation. By the end of the twelfth century, the _New Logic_ was pretty well assimilated, but then came Aristotle’s _Metaphysics_ and natural philosophy, with their Arabic commentators, the study of which at Paris was formally forbidden in 1210 and 1215. In 1231 the Pope requires them to be “examined and purged of all suspicion of error,” but by 1254 they are a fixed part of the curriculum in arts, not expurgated but reconciled by interpretation to the Christian faith. A generation later there is a recrudescence of Averroism, emphasizing the doctrine of the eternity of matter and the determination of earthly acts by the heavenly bodies; and two hundred and nineteen errors of this party were condemned in 1277 by the bishop of Paris, who took occasion to lament incursions into theology on the part of students of arts. Throughout this period the whole of Aristotle was taught and studied at Paris, and his method was used by Thomas Aquinas to rear his vast structure of scholastic theology. Others reserved for themselves a wide range of philosophic speculation, and in case of trouble they could save themselves by falling back on the doctrine that what was true in philosophy might be false in theology, and _vice versa_.