Between Newton and the Neo-Kantians: The Evolution of Absolute and Relational Space in 18th and 19th Centuries

Edward Slowik

Winona State University

Abstract: 
The topic of this presentation concerns the historical development of the concepts of absolute and relational space (or substantival and relational space) in the 18th and 19th centuries (i.e., that space is either an independent entity of some sort, or a mere relation among these entities). In the contemporary scene, the story that is often told about the genesis of the absolutist/relationist debate usually centers on two time periods: first, the seventeenth century, with Newton and Leibniz serving as the primary exemplars of, respectively, absolutism and relationism; and second, Mach and the twentieth century interpretations of General Relativity (where various positivist and neo-Kantian perspectives receive the main emphasis). But what happened to the ontology of space between Newton’s time and the modern spacetime setting? As will be argued, a major turning point in the development of these concepts was already in progress during Newton’s lifetime. Whereas Newton and Leibniz, and nearly all other natural philosophers in the 17th century, based there ontologies of space on God, albeit in diverse ways, that approach to space had been largely abandoned by the end of the eighteenth century. In its place, various approaches were investigated that strived to retain Newton’s distinction between absolute and relational space, but without accepting Newton’s underlying spatial ontology, namely, God. The British Empiricists were instrumental in this change, for their conception of philosophy puts the empirical aspects of space at the center of the debate on spatial ontology, a direction that has certain affinities with, and connections to, subjectivist construction of space later adopted by the German Idealists. Another major influence on the changing nature of the debate, related to the growing empiricist trend, revolves around the increasingly important role that physical theories played in shaping the content of an acceptable philosophy of space and time. In particular, Newton’s mechanics was seen by some, such as Euler and Kant, as a basis upon which to interpret or construct conceptions of space in a manner that obviates his concerns about space’s ontological groundings. Nevertheless, despite these attempts to reinterpret the Newton-Leibniz controversy on space for a new philosophical audience with different attitudes towards ontology, the majority of the theories of space offered in the 18th and 19th centuries would seem to steer a course that is difficult to track given the modern substantivalist and relationist categories. In short, space was often linked to a physical entity or process, and hence space found an ontological grounding of sorts in such doctrines as Wolffian monads, Boscovichian forces, the electromagnetic aether, and ultimately, the metric/gravitational field in General Relativity. Although this aspect of the history has been largely ignored by commentators, many of the current disputes in the philosophy of space and time that employ the substantivalist and relationist categories can learn much from what has, and has not, changed in the evolution of these categories during this neglected period.