An encyclopedia in the vernacular for the general reader: that seems to have been what the Antwerp townsclerk jan van Boendale had in mind when, in 1330, he wrote Der Leken Spiegel, "the laymen's mirror of the world." In four books Boendale discusses Creation; the life of Christ; the world's history from the beginnings down to Charlemagne; Heaven, Hell, etc. In Book Three, which is dedicated to moral precepts, there is a small chapter called "How writers should write and what they should pay attention to," which is one of the first medieval poetic treatises in the vernacular.' In the first paragraph of the text Boendale states that a genuine poet should be thoroughly schooled in Latin grammar, that he should be truthful, and that he should lead an honorable life. In the three hundred lines that follow, Boendale elaborates on each of these three requirements. The moral requirements for being a writer are the author's main concern, but he also dwells on a number of more strictly poetic issues. Special attention is paid to the question of veracity in historical texts and to the truthfulness of their authors.