When I think of God, when I think of him as existent, and when I believe him to be existent, my idea of him neither increases nordiminishes. But as it is certain there is a great difference betwixt the simple conception of the existence of an object, and the belief of it, and as this difference lies not in the parts or composition of the idea which we conceive; it follows, that it must lie in the manner in which we conceive it.

The Philosophical Works (ed. 1826)