The Role of Imaginary Cases in Ethics

This paper examines the rationale for the standard practice in ethics of arguing from imaginary cases to real ones. Challengeable aspects of this practice are exposed. One question is whether an imaginary case is being taken to establish a Rossian prima facie duty or a duty proper. Another is whether, once we have established the correct account of an imaginary case, we can be sure that another case similar to the first in all respects relevant to our account of the first must be given the same account, irrespective of other differences. A generalist will try to extract principles from the imaginary case and apply them to the real case. This paper argues that this is hopeless. Is particularism in a better situation? A possible line is that what the imaginary case reveals is the importance that certain features can have and may have in the real case before us. No more can be expected.