James observed that new ideas become interesting when they attach to something the learner already finds interesting. The teacher's craft is building that bridge.
It is tempting to divide subjects into the naturally interesting and the naturally dull. James rejected this. In his view, interest is mostly borrowed: an unfamiliar idea gains interest by being connected to something that already matters to the learner.This means the starting point of a lesson is the learner, not the syllabus. What do they already know, value or wonder about? A new concept introduced through a familiar experience, a local example or a real problem inherits some of the interest that experience already holds.
Once connected, interest grows. As learners gain competence, the subject itself begins to carry its own interest, and the bridge becomes less necessary. Early effort spent linking new material to existing interests pays back over time.
For teachers in diverse classrooms, this is an invitation to know learners well. Understanding their backgrounds, languages and everyday lives is not an extra; it is the raw material from which interest is built.