that the nature of God is unknowable—­except by means of a supernatural interference, which gives to men a new power of spiritual discernment, and “reveals” to them things which are “above reason,” although not contrary to it.  The theologian often shields certain of his doctrines from criticism, on the ground, as he contends, that there are facts which we must believe, but which it would be presumptuous for us to pretend to understand or to demonstrate.  They are the proper objects of “faith.”

But this view of the weakness of the intelligence when applied to supersensuous facts, is held along with an undisturbed conviction of the validity of our knowledge of ordinary objects.  It is believed, in a word, that there are two kinds of realities,—­natural and supernatural; and that the former is knowable and the latter not.

It requires, however, no great degree of intellectual acumen to discover that this denial of the validity of our knowledge of these matters involves its denial in all its applications.  The ordinary knowledge of natural objects, which we begin by regarding as valid, or, rather, whose validity is taken for granted without being questioned, depends upon our ideas of these supersensible objects.  In other words, those fundamental difficulties which pious opinion discovers in the region of theology, and which, as is thought, fling the human intellect back upon itself into a consciousness of frailty and finitude, are found to lurk beneath our ordinary knowledge.  Whenever, for instance, we endeavour to know any object, we find that we are led back along the line of its conditions to that which unconditionally determines it.  For we cannot find the reason for a particular object in a particular object.  We are driven back endlessly from one to another along the chain of causes; and we can neither discover the first link nor do without it.  The first link must be a cause of itself, and experience yields none such.  Such a cause would be the unconditioned, and the unconditioned we cannot know.  The final result of thinking is thus to lead us to an unknown; and, in consequence, all our seeming knowledge is seen to have no intelligible basis, and, therefore, to be merely hypothetical.  If we cannot know God, we cannot know anything.

This view is held by the Positivists, and the most popular English exponent of it is, perhaps, Mr. Herbert Spencer.  Its characteristic is its repudition of both theology and metaphysics as pseudo-sciences, and its high esteem for science.  That esteem is not disturbed by the confession that “noumenal causes,”—­that is, the actual reality of things,—­are unknown; for we can still lay claim to valid knowledge of the laws of phenomena.  Having acknowledged that natural things as known are merely phenomena, positivism treats them in all respects as if they were realities; and it rejoices in the triumphant progress of the natural sciences as if it were a veritable growth of knowledge.  It does not take to heart the phenomenal nature of known objects.  But, having paid its formal compliments to the doctrine of the relativity of all knowledge, it neglects it altogether.