There can be few more celebrated principles in contemporary political life than freedom – and few more bitterly weaponised. Our ability to choose and shape a preferred pathway through life is arguably the most powerful social and political value of the last 250 years.2 According to economist Amartya Sen, freedom is foundational to human development – instrumental to the functioning of participatory politics and to the engines of economic growth, but intrinsic, too, to the essence of what the ‘good society’ represents. In the early 21st century, an ethics of freedom has come to underpin our most basic conception of how we should be governed, and how we envisage our everyday lives (Rose, 1999).

Yet freedom is inherently paradoxical. It is, as Hannah Arendt says, the unsquareable circle of conscience and consciousness, the collision between a causal universe and our irrepressible sense of will – humanity suspended somewhere between angel and beast (Arendt, 1961). Freedom is an endlessly contested construct, an aspiration incapable of completion but requiring constant effort and attention in balancing the societal values of the individual and the collective, the particular and the universal (Gallie, 1955). The language of freedom exercises great moral and symbolic weight yet the word is, in and of itself, curiously void – given sense only by the objects and objectives to which it is attached. Freedom from what or whom? Freedom to do what, for what purpose? Isaiah Berlin notes over 200 working definitions of the word – its forms and representations inevitably selective and ideological, capable of legitimising everything from extreme libertarianism to totalitarian control (Berlin, 1969). The history of freedom is, if nothing else, a struggle for meaning.

In the course of two and a half centuries, a proliferation of philosophical and sociological theories – of Kant, Rousseau, Hegel, Marx and Foucault, Hobbes, Locke, Hulme, Mill and Hayek, Montesquieu, Tocqueville, Berlin, Arendt and Sen – have created a densely woven, complex and contradictory field of ideas blending raw conjecture, metaphysical intuition and empirical observation about the possibilities of freedom – as MacGilvray puts it,