The idea of ‘sustainability’ received serious attention in the so-called Brundtland Commission Report that has many attractive features. In particular, it highlighted the importance of intergenerational justice while maintaining a concern for the poor of each generation and shifted the focus away from resources to human beings. I argue that this way of understanding sustainability, while a great improvement, is still incomplete. There are important grounds for favouring a freedom-oriented view, focusing on crucial freedoms that people have reason to value. Human freedoms include the fulfilment of needs, but also the liberty to define and pursue our own goals, objectives and commitments, no matter how they link with our own particular needs. Human beings are reflective creatures and are able to reason about and decide what they would like to happen, rather than being compellingly led by their own needs—biological or social. A fuller concept of sustainability has to aim at sustaining human freedoms, rather than only at our ability to fulfil our felt needs. Some empirical examples are given to illustrate the distinctive nature and the reasoned importance of seeing sustainability in terms of sustaining human freedoms and capabilities.