Elementary Latin instruction (almost the only formal education in the Middle Ages) depended on an outline of grammar attributed to the ancient grammarian Donatus. This textbook, commonly called a Donat, also included a set of moral proverbs called the Cato, again for a supposed author. These texts were used and modified through the entire early modern period, but there were also repeated attempts to replace them with more modern and useful textbooks, often designed with inexpert readers and the need for memorization in mind.