  Textbooks and encyclopedias are not necessarily contrasting genres, as sometimes encyclopedias were used as textbooks. In spite of being (again) based on Aristotle (and his commentators), some textbooks did provide more “untraditional” views by integrating material found in Aristotle (and his commentators) with material found in other  authors.[24]   Other textbooks provided untraditional views by their choice of what they retained and what they left out and how they paraphrased what they  retained.[25] 