In his recent book Waar geest is, is vrijheid [Where there is mind, there is freedom], Guus Labooy sets forth an original and intriguing argument, inspired by the work of John Duns Scotus, for substance dualism in the philosophy of mind. In this paper we argue that his argument, although worthy of serious attention, is under-supported. In section 2 we question the significance of the particular scotistic notion of freedom he uses in his argument, even though we agree with his premise that humans do possess freedom in the libertarian sense. In section 3 we argue that Labooy fails to make his key contention that significant freedom requires an irreducible immaterial soul sufficiently plausible. The key problem is that he does not consider the work of physicalists who also believe in libertarian freedom. In addition, it is not self-evident that an immaterial soul, as opposed to a physical body, can possess significant freedom. This requires argument. In section 4 we comment on Labooy’s specific conception of dualism and advise him to change it into a conception in which the soul — and not the composition of soul and body — is the human person, for the latter conception has absurd consequences.