With the entry into the gothic period the medieval book system experiences the most profound changes of its entire history. If, up to that time, it was bound up with clerical institutions (the monasteries and chapters), now new forces were at work which resulted in an enormous increase in book production: the scholarly activities that were organised in the universities, the increased practice of preaching, the deepening of religious life through mysticism, above all in the female religious orders, the spread of written education among the laity, and their interest in literature, especially in the vernaculars. Writing, of course, still continued in the religious communities, but a large part of the professional production of books passed over to the civilian professional scribes in the cities. Outside the world of books and of formal charters writing became a tool in daily life, for administration, trade and crafts, for which book-keeping became indispensable. In city schools writing and arithmetic were taught, and formulae for letters also belonged to the instruction. However, there were apparently still in the thirteenth and fourteenth centuries not a few canons and monks who excused themselves from the duty of witnessing legal transactions because of their inability to write.