Kant’s pre-critical possibility proof for the existence of God, which he develops in detail in the Beweisgrund from 1763/64, is often thought to have Spinozistic implications. One key reason for this is that Kant’s reasoning in the Beweisgrund appears to entail that God is extended or spatial. Kant argues that God exemplifies all fundamental or primitive predicates. Since he also treats extension as such a fundamental predicate, it straightforwardly seems to follow that God is extended. This paper argues that Kant’s argument in the Beweisgrund does not, in fact, lead to this Spinozistic conclusion. In other writings from the same period Kant distinguishes between concepts that are fundamental for us and concepts that are fundamental in themselves, and he even applies this distinction to the concepts of space and time. With this distinction in hand, Kant is equipped with the resources to block the Spinozistic conclusion that God is extended: he can accept that extension is a fundamental concept for us while simultaneously rejecting that extension is a concept fundamental in itself. Thus, extension need not be a predicate that is exemplified by God, and the Spinozistic threat can be averted.