Abstract
In this paper, I argue that Crusius’s criticism of Wolff’s theory of space and time relies on an underappreciated aspect of their accounts: the role of experience and common linguistic usage. Both of them claim that ontological concepts should conform to experience and to concepts of everyday use. However, in the case of space and time, Wolff departs from ordinary language, because, in his view, our everyday understanding of these concepts is imaginary and differs essentially from the philosophical one. Crusius tackles this divergence, and argues that the common notion of space and time is not imaginary and actually corresponds to the one yielded by philosophical analysis.