And this very fact--the unspeakable differences between man and man, nation and nation, as regards recognition the conscious possession of even elementary "moral and spiritual truth" (varying, as it perpetually does, as those external influences vary, and more or less perfect, according as that external "revelation," which, in some degree, and of some species, is indispensable, more or less perfect)--affords another indication of the ample utility of an external divine revelation, as well as of its possibility; and a proof that, if there be one, it is in harmony, again, with the conditions of human nature. And here I may employ, in further illustration, one of the analogies I adverted to a little time ago. Not only is the flower never independent of external influences for its actual development,--not only would it remain in the germ without them,--but we see that within certain limits, often very wide, the kind of external influence operates powerfully on the species, and on the individual itself;--according as it is in one climate or another,--in this soil or that,--submitted to culture or suffered to grow wild. It is needless to apply the analogy. While we see that the moral spiritual faculties of man no more than his other faculties can attain their development except in cooperation with some external influences, we also see that they exhibit every degree and variety of development according to the quality of those external influences. Is there then not even a possibility left for an external revelation? If the actual exhibition of any spiritual and religious phenomena in man not only depends on some external influences and culture, but perpetually varies with them, what would such a revelation be but a provision in analogy with these facts? But it is sufficient to rebut this gratuitous dictum, of an external revelation of "spiritual and moral truth being impossible," that some external influence is necessary for any development of the religious faculty at all. If the last be necessary, I cannot conceive how the other should be impossible. Nor is it any reply to say,--as I think has been abundantly shown in your debates with Harrington,--that any such external influences only make articulate that which already existed inarticulately in the heart; that they only chafe and stimulate into life "the ivory of Pygmalion's statue," to use his expression,--the dormant principles and sentiments which somehow existed, but were in deep slumber. That which makes them vital, active, the objects of consciousness and the sources of power, may well be called a "revelation." Nay, since it seems that, in some way, this outward voice must be heard first, I think it is more properly so called than the internal response of the heart. That is rather the echo.