The question is posed by Zygmunt Bauman in the Spring 2007 issue of Soundings. Bauman spells out two assumptions as the basis for a self-assertive left, and as explaining 'the left's ubiquitous and steadfast presence in modern forms of life':
The first assumption is that it is the duty of the community to insure its individual members against individual misfortune. And the second is that, just as the carrying capacity of a bridge is measured by the strength of its weakest support, so the quality of a society should be measured by the quality of life of its weakest members. These two constant and non-negotiable assumptions set the left on a perpetual collision course with the realities of the human condition under the rule of capitalism; they necessarily lead to charges against the capitalist order, with its twin sins of wastefulness and immorality, manifested in social injustice.