[4] Ontotheology, according to Kant (as interpreted by Iain Thomson), "was the type of transcendental theology characteristic of Anselm of Canterbury's ontological argument which believes it can know the existence of an original being [Urwesen], through mere concepts, without the help of any experience whatsoever".
This he argues in Being and Time, his later essay on "The End of Metaphysics", in his Introduction of 1949 to his Was ist Metaphysik?, and in his most systematic treatment of the problem of ontotheology, Identity and Difference, (1957).
As such, the nature of philosophy as a factually unknown and structurally unknowable path of thought is restricted by an economy of faith.
Ontotheology contributes to the human desire for mastery by presuming knowledge regarding the "first cause" of philosophy and the "highest being" of theology.
The "god of the philosophers" in ontotheology, whom Heidegger referred to as the causa sui ('self-caused') or the ens realissimum ('ultimate reality'), is an idol created by human thought and used for man's own purposes.
Heidegger cited that, in Leibniz's view, God, as the first existing cause of all being, is called reason and "what is to be posited as the ultima ratio of Natura, as the furthest, highest – and that means the first – existing reason for the nature of things, is what one usually calls God.
"[8] Heidegger uses the expanded expression "onto-theo-ego-logic" ("onto-theo-ego-logisch") in his lectures on Hegel in the Winter semester 1930/31 (GA 32:193).
The latter project takes its cue from Jacques Derrida's observation, "With or without the word being, Heidegger wrote a theology with and without God.