Wilhelm Schmidt proposed the theory of original monotheism as the origin of religion in the world saying that the earliest religions were based on one distant high God?

It was the Scottish anthropologist Andrew Lang who first proposed the idea of a high god that he believed existed among some of the simplest of contemporary tribes. The noted anthropologist Wilhelm Schmidt accepted and defended that hypothesis, which he no doubt felt was in line with his beliefs as a Catholic priest.

Wikipedia explains that primitive monotheism, "the hypothesis of a monotheistic 'Urreligion' from which non-monotheistic religions degenerated, is diametrically opposed to the evolutionary view of religion, another hypothesis which holds that religion progressed from simple forms to complex: first preanimism, then animism, totemism, polytheism and finally monotheism."

Schmidt's hypothesis of primitive monotheism was debated during much of the first half of the twentieth century, after which the hypothesis was rejected by academics. Most anthropologists have abandoned all evolutionary schemes like those of Schmidt and Pettazoni, for the historical development of religion, saying that they have also found monotheistic beliefs existing alongside other religious beliefs.