In Religion and Science Maulana Wahiduddin Khan explains that there are two kinds of knowledge: knowledge of things and knowledge of truth. So far as "things" are concerned, they display no attribute that cannot be elucidated by direct argument. But where truths are concerned, it is only indirect argument, which can throw any light upon them. Indeed, in the case of scientific truths, the validity of indirect, or inferential argument is a matter of general acceptance. Since religious truths are proved by the logic of similar inferential argument. It may legitimately be argued that they fall into the same intellectual bracket as scientific truths. Modern investigation has proved that the urge to be religious is a natural and insuppressible emotion in man. Attempts have been made to formulate a man-made religion, but in a universe where man is pathetically incapable of arriving at ultimate truths, this has been a failure. This was inevitable, for there is no man who is able, without divine guidance, to develop a religion, which is in complete correspondence with the truths of the universe for the benefit of the creatures who inhabit it.