At the basis of the educational organisation of these Orders would be the grammar schools. Novices were not accepted unless they had attained to a certain standard of education. The Dominican statutes of the thirteenth and fourteenth centuries required candidates to be examined "in moribus et scientia," and they were rejected if they were deficient in either.[580] Consequently, the instruction to be given by the master of the novices was mainly moral.[581] For the next grades of instruction, the convents were combined into groups. Common schools for special studies were established in one or more convents of each group.[582] The first of these grades was the "studium artium." At one time the study of arts was discouraged. "Students shall not study in the books of the Gentiles and philosophers though they may look into them occasionally."[583] The statutes of 1259 and 1261 indicate a different attitude. "Quot fratres juniores et docibiles in logicalibus instruantur."[584] No student was to be sent to a "studium artium" until he had been two years in the Order.[585] The next grade was the "studium naturalium." The period of study at this stage extended over two years at least.[586] The "studia naturalium" were less numerous than the "studia artium." There seem to be few traces of the existence of these in England, but Mr. Little has established that there was one at Lynn in 1397.[587] The "studium theologie" was the third grade. In these schools a period of three years might be spent, but the usual stay was for two. Mr. Little raises the question where such "studia" were to be found in England and considers that they may possibly have existed at Thetford in 1395, at Lincoln in 1390, at Norwich in 1398, at Ipswich in 1397, at Newcastle-on-Tyne in 1397, at Guildford in 1397, and at London in 1475.[588] The convents of Oxford and Cambridge stood at the head of the educational system. The statute of 1305 enacted that "No one shall be sent to a 'studium generale,' either in his province or out of it, unless in the order mentioned he has made sufficient progress in logic and natural philosophy, and has attended lectures on the 'Sentences' for two years in some 'studium particulare' and unless the testimony of the lector, cursor, and master of the students gives good hope that he will be fit for the office of lector."[589]