 However, Rousseau’s writings help Kant to the articulation of a practical philosophy that addresses many of the tensions in the Enlightenment. Kant follows Rousseau, and disagrees with empiricism in ethics in the period, in emphasizing human freedom, rather than human happiness, as the central orienting concept of practical philosophy. Though Kant presents the moral principle as a principle of practical reason, his ethics also disagrees significantly with rationalist ethics in the period. According to Kant, rationalists such as Wolff, insofar as they take moral prescriptions to follow from an end given to the will(in Wolff’s case, the end of perfection), do not understand us as autonomous in our moral activity. Through interpreting the faculty of the will itself as practical reason, Kant understands the moral principle as internally legislated, thus as not only compatible with freedom, but as equivalent to the principle of a free will, as a principle of autonomy. As noted above, rationalists in ethics in the period are challenged to explain how the objective moral order which reason in us allegedly discerns gives rise to valid prescriptions binding on our wills (the gap between is and ought). For Kant, the moral order is not independent of our will, but rather represents the formal constraints of willing as such. Kant’s account thus both avoids the is-ought gap and interprets moral willing as expressive of our freedom.