The modern psychology and the positivism as a methodology of science in general both emerged hand in hand in the middle of 19th century. At the beginning, they regarded human consciousness as the absolute basis of knowledge, i. e. the “consciousness worship”. The misunderstanding that the consciousness is evidently known led to a false conviction that they could know all that should be known in the world. Meanwhile, natural sciences continued researches in their own way upon their own material evidences. With the decline of introspectionist psychology, the material evidences unnoticedly succeeded the overconfidence in the old evidence of the consciousness. The process opened the way to a belief that the being in the world is exhausted within the realm of positivistic science, i. e. “onto-delusion”. However, the “consciousness worship” is still in effect, because even the positivism based on material evidences cannot avoid depending upon “normal” human consciousness as a premise of objectivity. Psychology has played the central role in this delusional process. We have no right to demand universal validity from the beginning in any method of science.