“The thirteenth-century Franciscan, St. Bonaventura, said that there were four ways of making books: ‘A man might write the works of others, addding and changing nothing in which case he is simply called a ‘scribe’ (scriptor). Another writes the work of others with additions which are not his own; and he is called a ‘compiler’ (compilator). Another writes both others’ work and his own, but with others’ work in principal place, adding his own for purposes of explanation; and he is called a ‘commentator’ (commentator) … Another writes both his own work and others’ but with his own work in principal place adding others’ for purposes of confirmation; and such a man should be called an ‘author’ (auctor).’ ”

Quoted in Elizabeth Eisenstein, The Printing Press as an Agent of Change, Communications and Cultural Transformations in early-modern Europe, Cambridge UP, 1979, p. 121/122