Attaining the Goals
Given the foregoing, what can be said about the teacher's appropriate role or roles for effectively engaging students in the discussion of controversial issues? I want to emphasize that I regard the best teaching as an artful, although rational, pursuit rather than a formulaic exercise of mechanically applying prescribed techniques.
Part of the rational art of engaging students in discussion of controversial issues is judging what roles to play at what time in a lesson or unit. We should not assume, for example, that a unit focused on disciplined inquiry requires that the teacher unrelentingly act only as presiding judge, cross-examiner, or in some other set role. What is most critical is that the teacher's role at any point be constructed in a manner likely to help students attain the goals or objectives central to that instructional moment.
Not only does every issue have more than one side, practically every issue has more than two. There were blacks who owned slaves and whites who opposed slavery but hated blacks; there were slaveholders who went to church on Sunday and had religious justification for the horrific punishments they dished out, and there were slaveholders who taught their slaves to read and fantasized about freeing them. The Revolution had Patriots and Loyalists, but also people who wanted the whole thing to go away, and the Patriots sniped at each other about how patriotic they were. Use a variety of primary sources to get students talking about gradations of opinion rather than either/or.