[Illustration: Fig. 11. From M. Hundt, _Antropologium, de hominis dignitate natura et proprietatibus_, Leipzig, 1501. The figure shows the ten layers of the head, the cerebral ventricles and cranial nerves, and the relation of the nerves to the senses.] [Illustration: Fig. 12. THE LAYERS OF THE HEAD From the _Anatomia_ of Johannes Dryander, Marburg, 1537.] The ten parts or layers of the head are a commonplace of the anatomy of the period, taken from Avicenna. We may illustrate the division by the crude contemporary diagram of Fig. 11, which is improved in the later drawing reproduced in Fig. 12. Manfredi’s account of the brain itself is amplified from Mondino. The division of this organ into three ventricles, each associated with a corresponding division of the mental functions, was very familiar to medical writers of the fifteenth century. The idea is found among Western writers as early as St. Augustine (354-430), and is encountered in the writings of Roger Bacon (1214-94). It had long been popularized in mediaeval psychology by the writings of Albertus Magnus (1206-80). The anatomical distinction is found in Haly Abbas, Avicenna, and Rhazes, and in some of the best MSS. of the latter writer a rough diagram of the ventricles is given.[188] These writers are all clearly indebted to the anatomy of Galen,[189] but on the psychological side Albertus Magnus probably drew mainly either from Ghazali[190] (1059-1111), who in turn derived his inspiration from Nemesius (fourth century) and Johannes Damascenus (died 756), or else from early writers of the Salernitan tradition, such as Constantine[191] (eleventh century), or Petrocello[192] (twelfth century), who drew largely on Theophilus (seventh century).[193] [Illustration: Fig. 13. From _Illustrissimi philosophi et theologi domini Alberti magni compendiosum insigne ac perutile opus Philosophiae naturalis_, Venice, 1496, showing the ventricles of the brain.] This outline of a tripartite division of the brain and its cavities was closely followed throughout the Middle Ages, as was also the curiously naïve and excessively ‘materialistic’ psychology to which it gave rise, and which Manfredi adopts. We illustrate his views of the relationship of the different parts of the brain and their parallelism in mental processes, from a series of diagrams extracted from contemporary works (Figs. 13-18). [Illustration: Fig. 14. Diagram of the senses, the humours, the cerebral ventricles, and the intellectual faculties. MS. Sloane 2156, folio 11 recto, in the British Museum, being a copy written in 1428 of the _De Scientia Perpectiva_ of Roger Bacon] [Illustration: Fig. 15. From K. Peyligk’s _Philosophiae naturalis compendium_, Leipzig, 1489. Illustrating the general ideas on anatomy current at the Renaissance.] [Illustration: Fig. 16. The cerebral ventricles from above and from the side. According to K. Peyligk, _Philosophiae naturalis compendium_, Leipzig, 1489.]