To avoid a worsening of the current economic crisis, and to prevent future crises related to ecological constraints and social imbalances, there is a need to change the decision-making processes and related power structures, in order to envisage a new style of development. Indeed, three constituents of such a style are already in place. Firstly, the theoretical approach looks at the capabilities of people, at their freedom to choose what they value, and at their agency. Second, in operational terms, a solidarity-based economy regularly invents relevant solutions for overcoming changing social and ecological issues by means of a defined set of values: responsibility, equity and recognition, and the way people interact and behave. Third, sustainable development provides a global conceptual framework through its human dimension (i.e. the reinforcement of personal capabilities), and its social dimension (intra- and intergenerational equity, poverty and inequality traps, vulnerability and social exclusion). This paper sets out to show how these three constituents interact to generate a new style of development, which could influence the future design of public policies.