10. Mind has evolved because the universe has evolved. Whether mind is a part of the universe, or all of it, or only an attribute of it, it is, in any case, inextricably mixed up with it. And, since the universe as a whole has evolved, it is improbable that any part of it or anything pertaining to it has remained impassive to the general tendency. There are no solids. Nothing stands. The whole universe is in a state of fluidity. Even the ‘eternal hills,’ the ‘unchanging continents,’ and the ‘everlasting stars,’ are flowing, flowing ever, slowly but ceaselessly, from form to form. So is mind. Indeed, if there is anywhere in the folds of creation a being such as the one whom man has long accused of having brought the universe into existence, we may rest assured that even he is not sitting passively apart from the enormous enterprise which he has himself inaugurated. The evidence is conclusive. The evolution of mind is supported by a series of facts not less incontrovertible and convincing than that by which physical evolution is established. The data of mental evolution are not quite so definite and plentiful as those of physical evolution. But this is due to the greater intangibility of mental phenomena and to the backward condition of the psychological sciences, especially of comparative psychology. Mental phenomena are always more difficult to deal with than material phenomena, and hence are always more tardily attended to in the application of any theory. But taking everything into account, including the close connection between physical and psychical phenomena, it may be asserted that it is not more certain that the physical structure of man has been derived from sub-human forms of life than it is that the human mind has also been similarly derived. Man is the adult of long evolution. The human soul has ancestors and consanguinities just as the body has. It is just as reasonable to suppose that the human physiology, with its definitely elaborated tissues, organs, and systems, is unrelated to the physiology of vertebrates in general, and through vertebrate physiology to the physiology of invertebrates, as to suppose that the states and impulses constituting human nature and consciousness began to exist in the anthropic type of anatomy and are unrelated to the states and impulses of vertebrate consciousness in general, and through vertebrate consciousness to those remoter types of sentiency lying away at the threshold of organic life. Human psychology is a part of universal psychology. It has been evolved. It has been evolved according to the same laws of heredity and adaptation as have physiological structures. And it is just as impossible to understand human nature and psychology unaided by those wider prospects of universal psychology as it is to understand the facts of human physiology unaided by analogous universalisations.