The scientific mind instantly grasps the inherent reasonableness of the existence of superphysical beings. Writing on the subject of energy, Nicola Tesla says: "We can conceive of organized beings living without nourishment and deriving all the energy they need for the performance of their life functions from the ambient medium.*** There may be *** individualized material systems of beings, perhaps of gaseous constitution, or composed of substance still more tenuous. In view of this possibility--nay, probability--we cannot apodictically deny the existence of organized beings on a planet merely because the conditions on the same are unsuitable for the existence of life as we conceive it. We cannot even, with positive assurance, assert that some of them might not be present here in this our world, in the very midst of us, for their constitution and life manifestation may be such that we are unable to perceive them."[N] Alfred Russell Wallace, who was called "the grand old man of science," wrote in one of his latest books: "I think we have got to recognize that between man and the ultimate God there is an almost infinite multitude of beings working in the universe at large, at tasks as definite and important as any we have to perform on earth. I imagine that the universe is peopled with spirits--that is, with intelligent beings with powers and duties akin to our own, but vaster. I think there is a gradual ascent from man upward and onward." While the scientist, still lacking the absolutely conclusive evidence, goes only to the point of asserting that it is reasonable and probable that supermen exist, the occultist asserts it as a fact within his personal knowledge.[O] So we have the direct testimony of the occultists, the endorsement of the scientists as to its probability, and, perhaps the most important of all, the inherent reasonableness of the idea.