G. W. Leibniz was a philosopher caught up in both the scientific and theological disputes of his day. Here I argue that a set of common concerns underlay hisengagement within two seemingly very different disputes: that with Newton over the nature of space and time, and that with Socinians over the Christian doctrineof the Trinity.First, Leibniz’s objections to Newton’s conception of space and time were linked to his objection to Newton’s model of the mind with which they was linkedbecause of Newton’s attempt to find support for his notions of absolute space and time by treating them as attributes of an infinitely extended immaterial God.Significantly, Newton had himself been a defender of the anti-trinitarian heresy of Arianism, and Leibniz’s alternative model of mindedness was in turn tied tohis trinitarian theology, as he saw the idea of three persons in one God as providing a model for human self-consciousness in which the identity of thereflecting and reflected upon thinking subject must be maintained. We can see within Leibniz’s triune model of self-consciousness the kernel of laterintersubjective models of human intentionality developed within the period of German Idealism.