Renaissance humanism was an activity of cultural and educational reform engaged in by civic and ecclesiastical chancellors, book collectors, educators, and writers, who by the late fifteenth century began to be referred to as umanisti – "humanists". It developed during the fourteenth and the beginning of the fifteenth centuries, and was a response to the challenge of scholastic university education, which was then dominated by Aristotelian philosophy and logic. Scholasticism focused on preparing men to be doctors, lawyers or professional theologians, and was taught from approved textbooks in logic, natural philosophy, medicine, law and theology. There were important centres of humanism at Florence, Naples, Rome, Venice, Mantua, Ferrara, and Urbino.