Abstract
In this paper I challenge the common view that early in his career (1679-1695) Leibniz held that space and time are well-founded phenomena, entities on an ontological par with bodies and their properties. I argue that the evidence Leibniz ever held that space and time are well-founded phenomena is extremely weak and that there is a great deal of evidence for thinking that in the 1680s he held a position much like the one scholars rightly attribute to him in his mature period, namely, that space and time are merely orders of existence and as such are purely abstract and occupy an ontological realm distinct from that of well-founded phenomena. In the course of arguing for this interpretation, I offer an account of the nature of Leibnizian phenomena which allows Leibniz to hold the view that space and time are phenomena, while at the same time thinking of them as abstract, ideal orders of existence.