The concept of ‘underclass’ evokes a multiplicity of attitudes and beliefs about its meaning, existence, causation and, therefore, its resolution. This paper draws upon the philosophy of the social sciences to explicate the contending philosophical perspectives on the ‘underclass's’ causation and resolution by reference to a taxonomy of methodologies, so enabling the articulation of each methodology's analytical strengths and weaknesses when used to investigate the ‘underclass’. The conclusion drawn is that policy analysts must be critically reflective before they seek to describe, explain, understand, judge and address ‘underclass’-related problems and issues by drawing upon any theories and methods grounded in anyone of these contending methodological families.