But now, athwart both the Hellenic and the Christian factors of our lives, the first apparently so clear and complete and beautiful, the latter, if largely dark and fragmentary, so deep and operative, comes and cuts a third and last factor, that of Science, apparently more peremptory and irresistible than either of its predecessors.[32] For both the former factors would appear to melt into mid-air before this last one. _They_ evidently cannot ignore _it_; _it_ apparently can ignore _them_. If Metaphysics and Religion seem involved in a perpetual round of interminable questions, solved, at most and at best, for but this man and for that, and with an evidence for their truth which can be and is gainsaid by many, but cannot be demonstrated with a peremptory clearness to any one: Science, on the other hand, would appear to give us just this _terra firma_ of an easy, immediate, undeniable, continually growing, patently fruitful body of evidence and of fact. And not only can Metaphysics and Religion not ignore Science, in the sense of denying or even overlooking its existence; they cannot apparently, either of them, even begin or proceed or end without constant reference, here frank and open, there tacit but none the less potent, to the enterprises, the methods, the conclusions of the Sciences one and all, and this even in view of establishing their own contentions. And more and more of the territory formerly assigned to Metaphysics or Religion seems in process of being conquered by Science: in Metaphysics, by experimental psychology, and by the simple history of the various philosophical systems, ideas, and technical terms, and of the local and temporal, racial and cultural antecedents and environments which gave rise to them; in Religion, by an analogous observation and study of man in the past and present, of man studied from within and from without. 1. _Three characteristics of this scientific spirit._