In this chapter, we trace the historical and intellectual origins of system justification theory, summarise the basic assumptions of the theory, and derive 18 specific hypotheses from a system justification perspective. We review and integrate empirical evidence addressing these hypotheses concerning the rationalisation of the status quo, the internalisation of inequality (outgroup favouritism and depressed entitlement), relations among ego, group, and system justification motives (including consequences for attitudinal ambivalence, self-esteem, and psychological well-being), and the reduction of ideological dissonance. Turning to the question of why people would engage in system justification--especially when it conflicts with other interests and motives--we propose that system-justifying ideologies serve a palliative function in that they reduce anxiety, guilt, dissonance, discomfort, and uncertainty for those who are advantaged and disadvantaged.