The notion of societal structural principles is the foundation stone of Dooyeweerd’s social philosophy, and of the political and legal philosophy grounded in it, yet it has so far received little detailed critical analysis or constructive reformulation among reformational scholars. The aim of this paper is the modest one of illustrating the kind of analysis still to be done if the notion is to be put to more constructive use within social theory. I shall say little about the epistemological or methodological implications of the notion, concentrating on its central ontological problematics. I shall do so by discussing the notion with special reference to its specific application to one particular societal structure, namely the state. Part I analyses Dooyeweerd’s general account of the notion of societal structural principles. I identify there a number of critical problems running through the paper, especially: a) the problem of how structural principles secure the internal unity of a societal structure; b) the distinction between the invariant character of societal structural principles, and the variable forms in which they are positivised; and c) the undeveloped link between societal structures and the structure of the human person. Part II illustrates these problems (especially the second) in relation to Dooyeweerd’s account of the structural principle of the state. Part III briefly sketches the direction of a possible reformulation of the notion of societal structural principles in the light of a more fully elaborated philosophical anthropology.