Challenging the claim that policy of gender separation on buses does not imply segregation and discrimination against women but rather an innocent concern for the cultural concept of modesty, this Paper attempts first to analyze and refute the respective arguments presented by Professor Harel by establishing counter arguments and examining counter examples which may produce different conclusions. At its second stage the paper proposes a broader field of analysis for scrutinizing the justifications for gendersegregated practices that is based on considerations of rationality. Its main thrust directs to the claim that from a liberal point of view, the difference between acceptable and non-acceptable practices should be depended upon two conditions: a) the rational justification of the practice. b) Its immunity to the burden of harm or oppression towards helpless individuals or groups. At its third and final part, the Paper attempts to produce a careful definition of the cultural meanings implied by the practice of gender separation. By proposing alternative conceptual structure of explanation, based on cultural phenomenological analysis, it aims to expose the deep discriminatory structure of power-relations between men and women in traditional societies, including the Ultra-Orthodox community, as exemplified by the practice of gender separation.