that while the professional astronomer, biologist, or physicist each adds to our knowledge of the subject that falls within his respective department, we owe little or nothing of our knowledge of the nature of religion to the professional theologian. To put the whole matter in a sentence, the study of religion must be affiliated to the study of life as a whole. If possible, we must get at the determining factors that lead one person to expend his energy on religion and see supernatural influence in a thousand and one details of his life, while another person, with apparently the same mental qualities, finds complete satisfaction in another direction, and is conscious of no such supernatural influence. It is scientifically inadmissible to posit a "religious faculty" organically ear-marked for religious use. Something of this kind is evidently in the minds of those who explain Darwin's agnosticism as due to atrophy of his religious sense, consequent on over-absorption in scientific pursuits, and who also argue that the "religious faculty," like a physiological structure, increases in efficiency with use and atrophies with disuse. There is no reason for believing that, had Darwin been profoundly religious, his mental qualities would have been different to what they were. They would have been expressed in a different form, that is all. As I have already said, there are no such things as specifically religious qualities of the mind. There may be hope or fear or love or hatred or terror or devotion or wonder in relation to religion, but they are precisely the same mental qualities that meet us in relation to other things. The old "faculty" psychology is dead, and the religious faculty must go with it.[9] Mental qualities may be roused to activity in connection with a belief in the supernatural, or they may be expressed in connection with mundane associations. Even the belief in the supernatural is only an expression of the same qualities of mind that with fuller knowledge result in a scientific generalisation. Whatever be the exciting cause, mental qualities themselves remain unchanged. In the present enquiry we are not concerned with a disproval of the religious idea, but with an examination of the conditions of its expression; less with the varieties of religious experience than with the nature of its manifestations. How far may religious experience be explained as a misinterpretation of normal non-religious life? To what extent have pathological nervous states influenced the building up of the religious consciousness? There can be no question that the last-named factor is an important one. This is admitted by Professor James in the following passage:--