 Williams’ denial of the possibility of external reasons—understood in light of his naturalism and his anti-systematic outlook—thus underwrites and supports his views on a whole range of other matters. And though the internal reasons thesis too is, in an important way, a negative thesis, it is arguably the cornerstone of a more robust, positive conception of our practical lives. While he only defended the negative condition in print, there is evidence that Williams actually believed that the right kind of strong desire is a sufficient condition for the possession of a practical reason. In Ethics and the Limits of Philosophy, he briefly opined that "desiring to do something is of course a reason for doing it," (1985:19), and he developed a theory of practical necessity according to which our deep commitments ("ground projects") necessarily constrain and direct our practical rationality (MSH 17). 