We present a deductive theory of space-time which is realistic, object
ive, and relational. It is realistic because it assumes the existence
of physical things endowed with concrete properties. It is objective b
ecause it can be formulated without any reference to knowing subjects
or sensorial fields. Finally, it is relational because it assumes that
space-time is not a thing, but a complex of relations among things. I
n this way, the original program of Leibniz is consummated, in the sen
se that space is ultimately an order of coexistents, and time is an or
der of successives. In this context, we show that the metric and topol
ogical properties of Minkowskian space-time are reduced to relational
properties of concrete things. We also sketch how our theory can be ex
tended to encompass a Riemannian space-time.