The freedom of association is enshrined in international conventions and state constitutions, and it has triumphed in many statutes and judicial decisions around the world. Association in the labour context can be viewed as yet another fulfilment of the general freedom to associate, as are the association of shareholders, political party members, social clubs or social movements. However, it is also regarded as a unique right that constitutes a central pillar for governing the labour market; a right intended to achieve goals such as equality, emancipation and dignity. Within the domains of this interpretation, it has been argued that the logic of association on labour’s side is different from that on capital’s side (Offe and Wiesenthal 1980). This book goes further, to argue there are two distinct logics of association on labour’s side, and as the title suggests – two logics of trade union representation. The one logic is that of workers coming together, acting to fight for their rights. The other logic is that of trade unions and employers’ associations, sometimes together with high-ranking officials of the state, negotiating labour market conditions. In both logics, membership is essential for the status, functioning and efficacy of the trade union. This is the unifying feature of both logics, singling out trade unions from other forms of association with similar objectives. Hence, the pivotal reference for understanding that the two logics of labour’s collective action is centred on membership. However, membership and its derivative traits – democracy, accountability, power and legitimacy – work in different ways.