Time is one of the most enigmatic notions philosophers have ever dealt with. Once subjected to close examination, almost any feature usually ascribed to time, leads to a plethora of fundamental and hard to resolve questions. Just as philosophers of the eighteenth-century attempted to take account of revolutionary developments in the physical sciences in understanding space, life, and a host of other fundamental aspects of nature (see Jones, Gaukroger, and Smith in this volume) they also engaged in fundamental and fruitful (...) controversies about the nature of time spurred by Newton and others (see Schliesser and Schabas in this volume). In this article, I will attempt to trace the general outlines of these controversies. Special attention will be given to a question that was central for many eighteenth century philosophers and is somewhat less prominent in contemporary, twenty-first century, debates on the nature of time, i.e., whether time can be reduced to, grounded by, or explained through other more basic elements. The concept of time is commonly discussed – both in eighteenth and twenty first century philosophy – in analogy to space. Here I will attempt to focus on time and address the analogies to space only when relevant. This attitude is motivated both by the need to provide as detailed an account as possible of time in the allocated textual space, and by the various dissimilarities between space and time. While space and time can be fruitfully compared and contrasted, the use of metaphors taken from one domain to clarify features belonging to the other domain has the real potential of leading us astray by unconsciously and seamlessly taking metaphorical language in a literal sense. In the first part of this essay, I will discuss the famous debate between Newton, Leibniz and Clarke on the nature of space and time. The second part will address Hume’s understanding of time and the relation between time and causation. In the third and final part, I will discuss Kant’s views on the relation between time and causality, place them in the context of his predecessors, and then examine Salomon Maimon’s attempt to revive the Leibnizian program of reducing time to concepts, within the framework of Kantian philosophy, broadly conceived. (shrink)