ABSTRACT
Even an impossibility can be thought about, talked about, discussed, and be considered in ways that treat it merely as an object of thought. It is sometimes suggested that thought experimentation is impracticable when the projecting suppositions at issue are too unrealistic: too bizarre and overly hypothetical. A philosophical thought experiment must take care not to saw off the very limb on which its suppositions hang. And this is not just because suppositions that contemplate considerations of extreme scarcity are too outlandish and farfetched for contemplation but because the course of their development has designed the ethical concepts and principles with very different sorts of situations in view. These farfetched hypotheses in that specific deliberative setting are inappropriate and will be unable to meet the dialectical needs of the situation. Suppositions that unravel and demolish the very concepts with which they are concerned are self-destructive.
