This chapter illustrates how the psychology of the Tractatus is incorporated into the Summa de anima and builds on the exposition of the Tractatus provided in Chapter 5 with a view to explaining how precisely John of La Rochelle conceived the operation of the senses and the human mind. The chapter argues that John used Avicenna to endorse an ‘active’ theory of cognition in which innate categories of the mind, later known as transcendentals, play a role in shaping human understanding of the senses, which nonetheless provide crucial material to be rendered intelligible.