Despite recent neuroscientific research purporting to reveal that free will is an illusion, this paper will argue that agency is an inescapable feature of rationality and thought. My aim will not be to address the methodology or interpretation of such research, which I will only mention in passing. Rather, I will examine a collection of basic concepts which are presupposed by thought, and propose that these concepts are interrelated in ways that makes them both basic and irreducibly complex. The collection includes such concepts as belief, value, meaning, and truth. I will argue that free will belongs to this collection, and as such is also presupposed by thought. This proposal is opposed to a methodological tendency in analytic philosophy, to eliminate aspects of concepts which can’t be given a clear analysis, and to the wish of many empirical psychologists and cognitive scientists to reduce intentional/mental states to neurons and other mindless phenomena which they regard as more fundamental. Instead of offering a direct critique of either of these methodological attitudes, I will try to place the concept of freedom in its proper conceptual context, and make a positive case for its reality