e. The growth of the mind, which may be traced in the histories of religions and philosophies and in the thoughts of nations, is one of the deepest and noblest modes of studying it. Here we are dealing with the reality, with the greater and, as it may be termed, the most sacred part of history. We study the mind of man as it begins to be inspired by a human or divine reason, as it is modified by circumstances, as it is distributed in nations, as it is renovated by great movements, which go beyond the limits of nations and affect human society on a scale still greater, as it is created or renewed by great minds, who, looking down from above, have a wider and more comprehensive vision. This is an ambitious study, of which most of us rather 'entertain conjecture' than arrive at any detailed or accurate knowledge. Later arises the reflection how these great ideas or movements of the world have been appropriated by the multitude and found a way to the minds of individuals. The real Psychology is that which shows how the increasing knowledge of nature and the increasing experience of life have always been slowly transforming the mind, how religions too have been modified in the course of ages 'that God may be all and in all.' E pollaplasion, eoe, to ergon e os nun zeteitai prostatteis. f. Lastly, though we speak of the study of mind in a special sense, it may also be said that there is no science which does not contribute to our knowledge of it. The methods of science and their analogies are new faculties, discovered by the few and imparted to the many. They are to the mind, what the senses are to the body; or better, they may be compared to instruments such as the telescope or microscope by which the discriminating power of the senses, or to other mechanical inventions, by which the strength and skill of the human body is so immeasurably increased. II. The new Psychology, whatever may be its claim to the authority of a science, has called attention to many facts and corrected many errors, which without it would have been unexamined. Yet it is also itself very liable to illusion. The evidence on which it rests is vague and indefinite. The field of consciousness is never seen by us as a whole, but only at particular points, which are always changing. The veil of language intercepts facts. Hence it is desirable that in making an approach to the study we should consider at the outset what are the kinds of error which most easily affect it, and note the differences which separate it from other branches of knowledge.