These phenomena of the preparation of the human being for civilization and morality can be explained only on the supposition of a superior intelligence which has guided man's development in a definite direction, just as man guides the development of many animal forms. By a superior intelligence is not necessarily meant the supreme intelligence. The modern cultivated mind seems incapable of realizing between it and the Deity other grades of intelligence, which the law of Continuity would, however, force us to infer: and rejecting first causes for any and every especial effect in the universe, except in the sense that the action of any intelligent being is a first cause, we can still conceive that the development of the essentially human portions of man's structure may have been, in this sense, "determined by the directing influence of some higher intelligent beings acting through natural and universal laws."[27] "It is probable that the true law of this development lies too deep for our discovery." Wallace quotes, in support of his theory, some of Professor Tyndall's much-disputed statements,--to the effect that the chasm between the phenomena of mind and those of brain is impassable. "To say that mind is a product or function of protoplasm, or of its molecular changes, is to use words to which we can attach no clear conception. You cannot have in the whole what does not exist in any of the parts;[28] and those who argue thus should put forth a precise definition of matter with clearly enumerated properties, and show that the necessary result of a certain complex arrangement of the elements or atoms of that matter will be the production of self-consciousness. There is no escape from the dilemma,--either all matter is conscious, or consciousness is[29] something distinct from matter, and in the latter case its presence in material forms is a proof of the existence of conscious beings outside of, and independent of, what we term matter.