Answer: Hello there! I know that the context of this question is more leaning towards history in your eyes (based on the category chosen), but there's a term in psychology that fits this situation perfectly: extrinsic motivation.
Explanation:
Healthline explains that "Intrinsic motivation comes from within, while extrinsic motivation arises from external factors. When you are intrinsically motivated, you engage in an activity because you enjoy it and get personal satisfaction from doing it. When you are extrinsically motivated, you do something in order to gain an external reward."
Joachim is not reading books because of personal interest (intrinsic motivation). In fact, he does it only for the incentives he can gain from his teachers (.
Hopefully, this little blurb helps you out a bit! Have a good day! :o)