"You speak of my book as 'ill-judged and mischievous,' as 'furnishing aid to hosts of deceivers,' and you think it, 'in the present state of intellectual and moral disorder' on the subjects of which it treats, 'peculiarly dangerous.' "Truth, unless prematurely urged (John xvi. 12), is never ill-judged or mischievous. I did not go in search of this subject. It came up in the course of human events, and doubtless at the proper time and for a good purpose. I found it already controlling the belief of hundreds of thousands, engaging the attention of millions. This, if it presented no other claims, appeared to me to entitle it, before judgment pronounced, to diligent and respectful inquiry. Thus inquiring, I perceived, as you have done, 'intellectual and moral disorders' not unfrequently following in the train of its influence; yet, looking at it more closely, I became convinced that it produced good as well as evil. "Surveying the ground further, I found the arena occupied chiefly by partisans; some of these (shall I include yourself?) delving the good; others, in their hasty enthusiasm, overlooking the evil. The former seemed to me to forget that it is not by despising error that we correct it; the latter, that the new and the untried often run into error and extravagance. "Desiring, after twenty years of public life, some more tranquil and philosophical field of labor, I discovered none which appeared to promise more useful results than this. If, as you allege, 'all the phenomena are due to two, and only two sources--delusion and imposture,' these should be detected and exploded, as by carefully prosecuted researches every delusion and every imposture can be. If, as I believe, there be a foundation of truth underlying them, still there is imperative demand for the exercise of prudence and the precautions of due regulation. Lacking these, a source of good may eventuate in evil. Even if the phenomena, wisely followed up, may elevate morality and fortify religion, yet if these marvels are permitted to spread among us without chart or compass whereby to steer our course through an unexplored ocean of mystery, we may find ourselves at the mercy of very sinister influences. "As to the general question at issue between yourself and me, you admit the reality of Spiritual influences directly exerted by God upon human intelligence. So far as, from the Creator's work, we may judge His modes of action, these are mediate and by ministering agencies, not by direct intervention. "Why, then, should we regard the hypothesis of Spiritual interposition (Hebrews i. 14) as a baseless superstition?