Helen Steward is Professor of Philosophy of Mind and Action at the University of Leeds. Her interests include the metaphysics and ontology of mind and agency; the free will problem; the relation between humans and animals; and the philosophy of causation and explanation. She joined the University of Leeds in 2007, having previously been a Tutorial Fellow at Balliol College, Oxford for 14 years. She obtained a D.Phil. from Oxford University in 1992, a B.Phil. in 1988 and a BA in philosophy, politics and economics in 1986. In February 2015 she was awarded a Research Leadership Fellowship by the Arts and Humanities Research Council. Helen argues that determinism is incompatible with agency itself – not only the special human variety of agency, but also powers which can be accorded to animal agents. She offers a distinctive, non-dualistic version of libertarianism, rooted in a conception of what biological forms of organisation might make possible in the way of freedom.