I. I argue from all the analogies of the fundamental laws of the development of the human mind.  Nor do I fear to apply the reasoning even to the cases in which it has been so confidently asserted that there can be no revelation, on the fallacious ground that a revelation “of spiritual and moral truth” presupposes in man certain principles to which it appeals.  To possess certain faculties for the appreciation of spiritual and moral truth is one thing; to acquire the conscious possession of that truth is another; the former fact would not make an external revelation superfluous, or an empty name.  Every thing in the process of the mind’s development goes to show, that, whatever its capacities, tendencies, faculties, “potentialities,” (call them what you will,) a certain external influence is necessary to awaken its dormant life; to turn a “potentiality” into an “energy “; to transform a dim inkling of a truth into an intelligent, vital, conscious recognition of it.  Nor is this law confined to mind alone; all nature attests its presence.  All effects are the result of properties or susceptibilities in one thing, solicited by external contact with those of others.  The fire no doubt may smoulder in the dull and languid embers; it is when the external breeze sweeps over them, that they begin to sparkle and glow, and vindicate the vital element they contain.  The diamond in the mine has the same internal properties in the darkness as in the light; it is not till the sun shines upon it, that it flashes on the eye its splendor.  Look at a flower of any particular species; we see that, as it is developed in connection with a variety of external influences,—­as it comes successively under the action of the sun, rain, dew, soil,—­it expands in a particular manner, and in that only.  It exhibits a certain configuration of parts, a certain form of leaf, a certain color, fragrance, and no other.  We do not doubt, on the one hand, that without the “skyey influences” these things would never have been; nor, on the other; that the flower assumes this form of development, and this alone, in virtue of its internal structure and organization.  But both sets of conditions must conspire in the result.

It is much the same with the mind.  That it possesses certain tendencies and faculties, which, as it develops itself, will terminate in certain ideas and sentiments, is admitted; but apart from certain external conditions of development, those sentiments and ideas will, in effect, never be formed,—­the mind will be in perpetual slumber.  Thus, in point of fact, this controversy is connected ultimately with that ancient dispute as to the origin, sources, and genesis of human knowledge and sentiments.  I shall simply take for granted that you are (as most philosophers are) an advocate of innate capacities, but not of “innate ideas”; of “innate susceptibilities,” but not of “innate sentiments”; that is, I presume you do not contend that the mind possesses