A key purpose of higher education seminars is to support higher-order thinking, yet empirical evidence of how this is evidenced and scaffolded in higher education remains scarce. Building on previous work on identifying rhetorical and linguistic devices for argumentation, we found that higher-order thinking can be evidenced through using metaphors, linking ideas to personal experiences and emotional connections. Findings also suggest that the types of tutor questioning can support (or not) how students evidence their claims and demonstrate higher-order thinking. We conclude with recommendations for practice including greater teacher and student metacognitive awareness of the features of quality seminar discourse.