Although Professor Van Eikema Hommes' article “Grotius on Natural and International Law” contains some acute observations, it is submitted that it provides an incorrect view of Grotius' methodology, which results in a one-sided description of his system of international law. The aim of this paper is to criticize this view through a more careful exposition of Grotius' methodology, and from this to derive a broad insight into the basics of his law of nations, in particular the law of war and natural law, which will be assessed in the light of modern conceptions.