This paper first evaluates discipline classification schemes and general differences between disciplines associated with the natural sciences and those associated with the humanities. It then reviews research which either asked students how professors in these fields teach, observed teachers in their classrooms, or asked students to describe their reactions to professors teaching science and humanities classes. Findings include: more pauses in lectures by professors of the humanities; different attitudes toward and uses of grades; emphasis by students on the instructor's efforts to connect content to student's lives and clarity of presentation; a tendency for students to report that good humanities classes are those which "interest" them and good science classes those which they"understand"; and differences in personality and learning styles (convergers/divergers and assimilators/accommodators) of students choosing either science or the humanities. Three paradoxes are identified: (1) between the collaborative nature of scientific work and the lecture method of undergraduate instruction; (2) between lower grades in the sciences than the humanities despite higher college entrance scores of science students; and (3) between the different instructional styles of the fields despite similar student ratings of good teaching behaviors. The existence of these two cultures in the university suggests needed changes in institutional procedures in evaluating teacher effectiveness, awarding student honors, and curriculum organization. (Contains 27 references.) (DB)