The paper discusses Leonhard Euler’s theses in Reflections on space and time. After a brief introduction to the debate about the nature of space and time in the 17th and 18th centuries and Euler’s position in it (section 1), the paper advances two hypotheses. Based on an approach to Isaac Newton’s writings, it is argued that Euler understands the notion of “reflection” as a rational activity of thought (section 2). Furthermore, it is argued that Euler’s silence about the nature of (...) absolute space and time must be understood in the same way as Newton’s refusal to discuss the nature of gravity. Space/time and gravity exist; however, their natures are not accessible to the human mind (section 3). (shrink)

I propose that we interpret Kant’s argument from incongruent counterparts in the 1768 article ‘Concerning the Ultimate Ground of the Differentiation of Directions in Space’ in light of a theory of dynamic absolute space that he accepted throughout the 1750s and 1760s. This force-based or material conception of space was not an unusual interpretation of the Newtonian notion of absolute space. Nevertheless, commentators have continually argued that Kant’s argument is an utter failure that shifts from the metaphysics of space to (...) its epistemology, because he has no way to connect ‘directionality’ and ‘handedness’ to absolute space. This supposed failure is based on an understanding of absolute space in purely mathematical terms and as an absolute void that lacks any qualitative or dynamic features. If we recognize that Kant held that space had an intrinsic directional asymmetry then his argument successfully connects incongruent counterparts to absolute space. The presence of this notion in Kant’s pre-Critical thought is rarely noted, and its necessity in understanding his incongruence argument is novel. (shrink)

I argue that, by the time of his essay "Concerning the Ultimate Ground of the Differentiation of Directions in Space" (1768), Kant had come to question the status of the Principle of Sufficient Reason as a result, at least in part, of his recognition of the existence of incongruent counterparts. Though Kant's argument against absolute space based on the existence of incongruent counterparts has been much discussed in recent years, its importance as a useful benchmark by which to judge the (...) direction of Kant’s thinking during this period has gone unnoticed. This paper is a modest attempt to remedy this deficiency. (shrink)