The law of nature appears as a premise of the argument of the Two Treatises of Government. We know, too, that Locke intended it to appear as the conclusion to the Essay concerning Human Understanding, but that he broke off the attempt to establish it and suppressed the chapter in which the attempt was announced. We also know that he never completed any such demonstration of its contents, although he seems to have tried frequently enough, and that he rejected with some asperity the urgings of several friends, most especially James Tyrrell and William Molyneux, to complete and publish such a demonstration. We may also suspect that he wrote the Reasonableness of Christianity at least in part to fill the gap which this failure had left in his intellectual bequest to his contemporaries and to posterity. At a more intellectual level, we have an effective explanation of why Locke never completed such a demonstration in the fact that such a demonstration is not in principle possible and that the development of Locke's ideas had drawn the difficulties of such an effort sharply to his attention. There is, however, little agreement among interpreters of Locke's thought on the significance which should be attached to these facts. Not only interpretations with as extensive a priori components as those of Strauss and Macpherson which I have treated elsewhere, but even more cautious and sensitively documented treatments like those of Von Leyden and Abrams are in sharp conflict.