Sadly, those who accept supernatural claims do so on the say so of those who author or reiterate those claims, not on the basis of any objective evidence that impartial parties can discover and verify for themselves (hence presuppositionalism's disdain for so-called "autonomous reasoning"). And those who demand unearned authority in such manner already show their willingness to abuse the trust of their followers, taking such trust as license to make the story up as they go (for their followers show that they will believe anything on their leaders' say so). As we already know, men have five senses. It would literally be as easy as child's play to claim that there exists something which could only be perceived if we had the appropriate sixth sense, which is never named and which we lack anyway. If we had 200 sense modalities, one could always come along and assert the existence of something we'd need a 201st sense modality to perceive. But how did the one making these claims perceive it in the first place if he lacks that crucial 201st sense modality? Again, blank out. We will never be able to perceive what men imagine, because the imaginary is not real, and something needs to be real in order to be perceived by impartial witnesses. But such facts do not cause Bahnsen to pause and consider. He steamrolls right over them as he races towards a cliff.
So Bahnsen not only fails to address these concerns, he does not show that he is even prepared to consider them, perhaps because he never was concerned about them himself. And no doubt, he most likely did not want his readers to be concerned about such issues either, so he would be motivated to suppress them even if they did occur to him in the privacy of his own thoughts. Let's face it, most readers of Bahnsen's apologetics books would be looking to strengthen their faith - i.e., to quell doubts rather than invite them. So the first thing we can say here is that Bahnsen does not present a case for the supernatural. If "the supernatural" is given no positive case on its behalf by its own defenders, why would opponents need to assemble any case against it? If there is nothing to recommend a position, why would we need to bother refuting it? So long as Bahnsen fails to identify any means by which we can acquire awareness of "the supernatural" (he only tells us how we do not have awareness of it), and so long as he fails to produce a serious, objective method by which we can distinguish what he calls "the supernatural" and what he is merely imagining, then he has failed to produce even the rudimentary beginnings of a case for the supernatural.
What else can we say? We can also point out that supernaturalism cannot survive on a proper metaphysics. It is clear that supernaturalism assumes the primacy of consciousness metaphysics, for it affirms the existence of a supernatural consciousness which holds metaphysical primacy over any object distinct from itself. But even to say that such a consciousness exists, we implicitly make use of the opposite principle, namely that the objects of consciousness exist independent of consciousness: they are what they are regardless of what we know, think or imagine about them. Otherwise the proponent of supernaturalism claims that the supernatural consciousness of his imagination exists essentially because he wants it to. And any honest adult should be able to recognize without a lot of deliberation that wishing does not make it so. Already we can see that an insurmountable case against supernaturalism is at our disposal.
In spite of these points, which seem to have eluded Bahnsen’s finely tuned intellectual powers of brilliance and precision, the master apologist nonetheless sought to take on “the case against [the supernatural],” at least, whichever “case” is most easily defused. When confronting non-religious philosophers, Bahnsen prefers to go up against the lightweights, perhaps because they were the only ones he bothered to read:
Bahnsen acknowledges that a common criticism of supernaturalism is the lack of an epistemological methodology which can take us from what we do know in the “here and now” (i.e., by reference to the evidence of the senses) to the “suprasensible reality” that Bahnsen claims to know about. We will find below that his response to this type of objection is to remove such knowledge claims from the field of epistemology altogether, which is a most fatal move if there ever were one. It is pointed out that we do not perceive such a phenomenon, but the response to this is that we should not expect to perceive it and accept claims about in spite of our inability to perceive it. Bahnsen does not seem to be claiming that he possesses a mode of perception beyond the five that we know human beings to possess. That is a wise move, but it garners him no points. Regardless, as pointed out above, even if man possessed 150 sense modalities, what would keep the Bahnsens of the world from claiming the existence of something which could only be perceived if we had a 151st sense modality, which, it is acknowledged, we lack? Then as now, we would be told not to expect to perceive whatever it is that we could not perceive, but that it is there nonetheless. At any rate, Bahnsen is well aware that a major concern is how one could “know” what it is he and other religionists are talking about when they speak of “the supernatural,” and yet what does he provide to answer this concern? Does he identify the means by which he is (allegedly) aware of what he calls “the supernatural”? No, he does not. Instead, he seeks to undermine reliance on the sense modalities that we do have, pronouncing them tainted or even inadequate to begin with. But nowhere does he identify any kind of alternative, and nowhere does he prove the existence of what he calls “supernatural.” Again, he provides no positive case for “the supernatural.”
The most common philosophical reason advanced by unbelievers, from Kant to the Logical Positivists of our century, for antagonism to metaphysical claims is quite simply the allegation that "pure reason" apart from sense experience cannot itself provide us with factual knowledge. Metaphysical statements speak of a suprasensible reality which is not directly experienced or verified by natural science; it might be said quite baldly, then, that metaphysics is a kind of "news from nowhere." Those antagonistic to metaphysics argue that all informative or factual statements about the objective world must be derived empirically (based on experience, observation, sensation), and therefore human knowledge cannot transcend particular, physical experience or the appearance of the senses. (Always Ready, p. 184)
So again, when Bahnsen affirms the existence of “a suprasensible reality which is not directly experienced or verified by natural science,” he merely identifies the means by which we do not know “the supernatural,” but he resists indicating the means by which one could know “the supernatural.” It is, as he confesses, “a kind of ‘news from nowhere’,” only it’s not news at all. He gives us nothing by which we could distinguish this “[good] news” from fantasy and fiction. That is because it is fantasy and fiction. If there’s a difference between fact and fiction, then Bahnsen and other advocates of “the supernatural” need to explain how we can acquire knowledge of what they call “the supernatural” and distinguish it from mere imagination. One does not even need explicitly to “argue that all informative or factual statements about the objective world must be derived empirically (based on experience, observation, sensation)” in order to recognize a difference between fact and fiction. But if one does make the claim that “informative and factual statements about the objective world” can be informed without content originally gathered from the world by “experience, observation, sensation,” he needs to identify an alternative to these. What alternative does Bahnsen identify? That’s just the problem: he identifies no alternative.
The notion of “conclusions that apply outside the empirical realm” is a rather vague way to identify something one wants to defend. It identifies a contrast, but it does not necessarily imply objectivity. As I have pointed out several times already, anyone can imagine something that exists “outside the empirical realm.” But imagination is not an objective means of knowledge. Apologists will have to do better than this if they want their religious views taken seriously by rational thinkers.
According to Kant, metaphysical discussions trade in purely verbal definitions and their logical implications; hence they are arbitrary, suspended in the sky, and result in irresolvable disagreements. Metaphysical statements have no real significance. By nature, human knowledge is dependent on the senses, and thus reasoning can never take one to conclusions that apply outside the empirical realm. (Always Ready, p. 184)