This chapter shows that how Kant relates freedom, morality and rationality. It argues that Isaiah Berlin's attribution to positive freedom that only virtuous people are free does not apply to Kant because he links freedom, morality and rationality not in the narrow sense, but in an inclusive sense. This will add new insights about the meaning of rational self-determination and its relation to freedom. For Kant, having a will, acting for reasons and being a moral agent are equivalent and denote the distinctive feature of humans. The chapter focuses on whether Berlin's criticism of the positive conception of freedom applies to Kant. Berlin interprets the link between freedom, morality and rationality as implying that only rational actions are good and only good actions are free. Berlin interprets Kant's views on the inseparability of freedom, rationality and morality with respect to the narrow sense, the chapter also argues that the inclusive sense is the correct interpretation.