It has been said, and few would deny, that John Locke is as important as the founder of philosophical liberalism as he is as the founder of the empiricist theory of knowledge. Though he was a most versatile thinker, writing on philosophy, politics, medicine, education, religion, and economics, and on all these with the knowledge of an expert and the influence of an authority, his fame no doubt derives on the one hand from his treatises on Toleration and Civil Government, and from his Essay on Human Understanding on the other. Whenever these are expounded by scholars, the political writings are discussed independently of the Essay and the Essay independently of the political writings. The reason for this is obviously that scholars have seen very little connexion between Locke's principal works. This has been changed with the appearance of a manuscript in which are preserved eight essays on the law of nature written by Locke in Latin shortly after the Restoration of 1660 and thirty years before the appearance in print of his major works. This manuscript has been published by me, and it is now possible to recognize that Locke's two main bodies of doctrine, namely his political theory and his theory of knowledge, have a common ground and that this lies in his early doctrine of natural law. Admittedly, the notion of a natural law can be seen to be of central importance in his treatise on Civil Government and it also plays its part in the Essay.