Natural Law

In the era that followed the conclusion of the Thirty Years' War in 1648, it was generally held that the combined effects of Renaissance skepticism and the fragmenting effect of endemic confessional strife had destroyed the coherence of preexisting accounts of political sovereignty. The rights and duties of monarchy, most especially in respect to churches and the enforcement of doctrinal and liturgical uniformity, were left open to question and redefinition as Europe sought to come to terms with the permanence of confessional division and the necessity of its diplomatic recognition. How could sovereignty remain unified and cohesive when religious truth had become fissiparous? How could absolutism be redefined in a way that preserved unity of political decision-making while paying due pragmatic recognition to the complexities of the new European order?

Nowhere were these tensions more visible than in the Holy Roman Empire, the epicenter of the recent military conflict, and the most graphic illustration in its uneasy religious tessellation of the need to find a new legitimization for political sovereignty. It is therefore no accident that it was from this region that there emerged the most systematic attempts to re-unify politics with metaphysics and devise new explanations of the appropriate exercise of political and ecclesiological power by the ruler. The pathbreakers in this respect were Grotius and Hobbes, far more than René Descartes (1596–1650), whose relative silence on morals gave no clear assistance in this area. Grotius was admired and praised above all for showing first in a series of specific works on the legal implications and meaning of colonial acquisition, and second in his larger work of synthesis, On the Law of War and Peace (1625), that there were still general principles of natural law that could be discerned right across the spectrum of international customary law. These were accessible to all, and, crucially, would obtain even if God and God's revealed intentions for humankind were taken out of consideration. From Hobbes European readers drew the key arguments of what is generally known now as voluntarism: that laws of general validity arose from the imposition of a unified, sovereign, rational will rather than the progressive discovery of general principles benignly imprinted on humanity's consciousness in the form of innate ideas. It was in the combination of Grotius's arguments in favor of the possibility and content of universal natural law, and Hobbes's insight into how those laws may be isolated and implemented in contemporary, fragmented practical politics that produced a truly modern theory of natural law, associated with Pufendorf and Thomasius. It evoked in turn a powerful hostile reaction in the work of Leibniz and Wolff, which tried to rework the views of Aquinas in a different idiom.

The contest (for that is what it effectively became) between the voluntarism of Pufendorf and the essentialism of Leibniz was mainly played out within a framework of university disputation, but also spilled over importantly into the public arena in debates over such issues as confessional reunion. At stake here in essence was the way in which the principles of moral knowledge were obtained, an apparently recondite area of learning, but nevertheless one with crucial implications for method in all areas of modern philosophy. In his major work On the Law of Nature and Nations (1672), Pufendorf argued that humans gain knowledge of morals in a way that parallels the manner in which they devise languages, that is, through the imposition of categories and meanings to create shared, mutually accessible structures. God may give humans revealed truths, but this forms but one part of human duties; the majority of these duties are devised through unaided reason, which God gave to humans to use in this free fashion. From this initial insight, explicitly grounded in Stoic thought, emerges a complex analytical structure that frames an elaborately contractarian politics weighted heavily through the prudential calculations of individuals in an absolutist direction. It also resulted in a clearly articulated Erastian church politics, vesting the civil power with final control and powers of resolution in religious disputes.

In contrast to this, Leibniz and Wolff regarded the work of Pufendorf and his followers as an attempt to provide practical resolutions of disputes from poorly argued philosophical premises that either guilefully or ineptly justified secular voluntarism. In its place, Leibnizian posited an elaborately conceived metaphysical approach that sought to explain natural law in terms of divine justice and the "charity of the wise," arguing in essence that all practical morality can be derived from the reservoir of truth located in the perfect wisdom of God. Less daring in the practical politics with which it eventuated, Leibnizian natural law nevertheless performed virtuosic surgery on the corpse of Protestant-Aristotelian natural law, ensuring that Wolff's textbooks enjoyed equal credibility and popularity in both Protestant and Catholic universities until the later eighteenth century. Leibniz also pointed out disquietingly secular overtones in the work of the followers of Pufendorf that inhibited their unequivocal acceptance of their work even within Protestant Germany.