How-possible questions matter in philosophy because, as Nozick points out, ‘many philosophical problems are ones of understanding how something is or can be possible’. A response to a how-possible question that operates on all levels is what is called a multi-levels response. This chapter defends this approach to epistemological how-possible questions. A multi-levels response operates at three levels. Level 1 identifies means of acquiring the allegedly problematic knowledge. Level 2 is the obstacle-removing level, the level at which obstacles to the acquisition of knowledge by the proposed means are overcome or dissipated. Level 3 seeks to identify necessary background conditions for the acquisition of the relevant knowledge by the proposed means.
Keywords: how-possible questions, multi-levels response, Kant's problem, perceptual knowledge, anti-minimalism