Books are complex things.
Their purpose is the communication of thought, mainly through texts to be read but also through illustrations designed to expound or expand the message of the texts. Every text and every cycle of illustration has a meaning and a history of its own, the elucidation of which is work for historians of language, literature and art, who use many different kinds of evidence, both internal to the texts and illustrations themselves and external. They, in return, are under a similar obligation to understand the methods and potentialities of palaeography. The ultimate justification of palaeographical research lies in its power to contribute to the history of thought, and especially of the long historical process by which all classical and medieval literature and much of medieval art have been transmitted to the present. The exact place of palaegraphy in the history of thought will be easier to define when we have considered what aspects of the manuscript book are the concern of palaeography and of no other discipline.