Dante was first and foremost a poet, and is often ranked with Homer, Virgil, and Shakespeare. He is, however, interesting to the historian for other things than his flights of fancy and the music of his verse. He had mastered all the learning of his day; he was a scientist and a scholar as well as a poet. His writings show us how the world appeared about the year 1300 to a very acute mind, and what was the range of knowledge available to the most thoughtful men of that day. [Sidenote: Dante's use of Italian.] Dante was not a churchman, as were all the scholars whom we have hitherto considered. He was the first literary layman of renown since Boethius,[219] and he was interested in helping other laymen who knew only their mother tongue to the knowledge heretofore open only to those who could read Latin. In spite of his ability to write Latin, he chose the mother tongue for his great poem, _The Divine Comedy_. Italian was the last of the important modern languages to develop, perhaps because in Italy Latin remained longest intelligible to the mass of the people. But Dante believed that the exclusive use of Latin for literary purposes had already in his time become an affectation. He was confident that there were many people, both men and women, who knew only Italian, who would gladly read not only his verses but his treatise on science,--_The Banquet_,[220] as he poetically calls it. [Sidenote: Extent of Dante's knowledge.] Dante's writings indicate that mediæval scholars were by no means so ignorant of the universe as they are popularly supposed to have been. Although they believed, like the ancients, that the earth was the center around which the sun and stars revolved, they were familiar with some important astronomical phenomena. They knew that the earth was a sphere and guessed very nearly its real size. They knew that everything that had weight was attracted towards its center, and that there would be no danger of falling off should one get on the opposite side of the globe; they realized also that when it was day on one side of the earth it was night on the other. [Sidenote: Dante's veneration for the ancient writers.]