Such successes as Luis de Leon had hitherto won he owed mainly to his own talents.[30] Brilliant as he was, there is no reason to assume that he was personally popular in Salamanca.[31] It does not appear that he made any effort to win popularity; nor is it certain that he would have succeeded even if he had sought to win it. His temper was impulsive, his disposition was critical and independent; his tongue and pen were sharp and made enemies among members of his own order; moreover, he contrived to alienate the Dominicans, a powerful body in Salamanca, as in the rest of Spain. No doubt he had many admirers, especially among his own students. Yet the University, as a whole, stood slightly aloof from him, and before long in certain obscurantist circles cautious hints of latitudinarianism were murmured against him. For these mumblings there was absolutely no sort of foundation.[32] As might be inferred from the simple fact that he was afterwards chosen to be the first editor of St. Theresa's works, Luis de Leon was the most orthodox of men. His selection for this piece of work may have been due to the influence of the saint's friend and successor, Madre Ana de Jesús, who had the highest opinion of him.[33] But it was not often that he produced so favourable a personal impression; he had not mastered the gentle art of ingratiation; it is even conceivable that he did not strictly observe St. Paul's injunction to 'suffer fools gladly'.[34] Though fundamentally humble-minded, he was intolerant of what he thought to be nonsense: a quality which would perhaps not endear him to all his colleagues. He set a proper value on himself and his attainments; he was prone to sift the precious metal of truth from the dross of uninformed assertion; he had an incurable habit of choosing his friends from amongst those who shared his tastes. A good Hebrew scholar, he was on terms of special intimacy with Gaspar de Grajal and with Martin Martinez de Cantalapiedra,[35] respectively Professors of Biblical Exegesis and of Hebrew in the University of Salamanca. Frank to the verge of indiscretion and suspecting no evil, Luis de Leon scattered over Salamanca fagots each of which contained innumerable sticks that his opponents used later to beat him with. Lastly, he had the misfortune, as it proved later, to differ profoundly on exegetical points from a veteran Professor of Latin, Rhetoric, and Greek.[36] This was Leon de Castro, a man of considerable but unassimilated learning, an astute wire-puller and incorrigible reactionary whose name figures in the bibliographies as the author of a series of commentaries on Isaiah--a performance which has not been widely read since its tardy first appearance in 1571. The delay in publishing this work, and the contemporary neglect of it, were apparently ascribed by Castro to the personal hostility of Luis de Leon who, though he did not approve of the book, seems to have been perfectly innocent on both heads.[37]