White's justification surrounds the notion of reciprocity, which he argues is essential to egalitarian notions of co-operation and solidarity. Many on the political left, for example, support a society in which people are willing to give help to those who need it and, subsequently, are secure themselves that they will be looked after if they so need.
Following on from this, White argues that it is not necessarily inconsistent to apply the principle of reciprocity to welfare payments. If citizens can expect to be supported by others in times of need, it is only fair that this is bound by a duty to contribute back into that society. In the case of welfare, this often means being required to look for work/accept reasonable work if in receipt of social security.
However, White tempers this principle with important qualifications. It is only fair, he argues, to expect welfare recipients to accept certain duties if - and only if - certain background conditions are in place. This might include the guarantee to a decent minimum income, opportunities for work and recognition alternative forms of participation, such as caring. Without these conditions, White questions whether welfare conditionality can be fair. We would not expect slaves, to take an extreme example, to hold a duty to work in slave society. To do so would be to argue that "individuals have an enforceable moral obligation to co-operate in their own exploitation".
For me, White gets at the crux at why many people on the political left feel uneasy with the notion of welfare conditionality. It is not so much an issue with the principles of contribution and reciprocity which can underpin some forms of conditionality but, rather, the economic environment in which these conditions are enforced. In a labour market where jobs are both scarce and often of very low quality, can it be fair to impose a duty upon people to put themselves in this situation? Is it fair, in other words, to enforce people to oblige in their own humiliation?