Because of the numerous changes in the motivations and objectives of aid policy over the past decades, Jean-Michel Severino compares official development assistance (ODA) to a Hydra. Yet while today’s global “macro-social” complexities create new ground for international solidarity, he argues that a profound reconsideration of the objectives, measurements, policy content and financing modes of development assistance is not only necessary and welcome, but also inevitable. A new generation of shared, long-term goals is needed to set the pace for collective mobilisation by reconciling social concerns with concepts of public goods and global macroeconomic management, shifting the focus from finance only to more inclusive policy approaches. Yet the challenge, he sustains, is not only to define objectives, but to measure results against them. To this end, a new international measurement system is needed. Severino foresees a gradual shift in financing of public welfare, with the rich in all countries bearing the burden of financing for the poor, for instance through international taxation.