What's the best way to introduce undergrads to the idea that one can reason about ethical questions? Suggestions welcome. In the meantime, here's a nice passage from Scanlon's What We Owe to Each Other (pp.66-67):
"What grounds can I have for deciding that I was mistaken to think that something was a reason? How can I be justified in calling this a process of correction rather than merely a change in my reaction? To answer this we need to see what such a process may involve.
Suppose, for example, that you are enraged by your child's defiant and insolent behavior. This behavior seems to you a reason to strike the child. But is it a reason? What kind of reason would it be? Is violence appropriate because it creates fear or shows your power? Why is that desirable? Is it supposed to be good for the child, or simply to demonstrate something about you? If the latter, what does that imply or signify about your relations with the child? If the former, why think that the effects will be good? What alternatives are there, and what would their effects be? The process here is first to clarify what kind of reason this is supposed to be and then to see whether the initial tendency to take this as a reason stands the test of reflection. ...
[H]ow does the process that you went through support you in taking the later judgment to be the one that is correct? Here are two reasons. First, the later conclusion is supported by a clearer and more detailed conception of what the reason in question might be -- of exactly what it is that is supposed to count in favor of striking the child. Second, in virtue of this reflection, it is less likely to be affected by distorting factors such as your rage."