In this chapter, we analyse the features of textbooks that enable and facilitate their role as material agents in the classroom. Rather than analyse the ways textbooks are used in interaction with humans, we analyse the elements in the textbook itself that facilitate intra-action and the ensuing material agency. Based on a discursive analysis of self-assessment in one textbook and discussing that construct against the Finnish national core curriculum and previous research, we present an ‘ideal imaginary’ of classroom activities as construed in the textbook. This helps us understand the textbooks in their pedagogical ergonomics; i.e. as socio-material in the classroom. We conclude by discussing the ideological nature of the textbooks not only as describing, but materially constructing a learner agency that understands learning both as constructivist and behaviourist. This merging of pedagogic ideals promotes a particular kind of disciplined behaviour to the extent that learner behaviour and learning are inseparably intertwined.