In the 13th-century, western Europe rediscovered Aristotle's books on natural philosophy, or natural science ('Libri naturales'), and this caused an intellectual revolution. Despite being banned in Paris early in the century, they quickly became part of the curricula of universities. Oxford, where this manuscript was probably made, was a leading centre for the study of Aristotle. All students had to read set texts of Aristotle's treatises with commentary, of which this book is an example. It is exceptional, though, because it is quite richly decorated with unusual images. Furthermore, it belonged to Nicholas of Cusa, a German theologian and cardinal, in the 15th century. Being the most important of Aristotle's works on natural philosophy, his 'Physics' ('Physicorum') is the first in the textbook. It was a demanding text, considered to cover the ideas essential to understanding of the natural world. Students spent three terms on it, and it introduced ideas which contemporary scholars at Oxford were applying to theology. The third book of 'Physics' begins with a historiated initial (first letter bearing a picture) of a crowned woman holding a flowering sceptre who represents the concept of 'Nature'. What meaning the nude harpist on the long, curving tail of the 'Q' might have had (if it had any) is a difficult question, as is the rodent-like texture of the 'tail'. The page is arranged so that a few paragraphs of 'Physics' are written in the centre, with layers of commentary, including that of the 12th-century Arabian philosopher and scientist Averroes, coordinated around it.