Perception & transcendental theism

Thomas Nagel is a leading secular philosopher. He even admits to having a strong emotional aversion to God’s existence. He doesn’t want God to exist.

However, unlike many atheists, Nagel is a fairly independent thinker who frankly admits the inadequacies of the standard secular paradigm. For instance:

For the most creatures, however, objectivity extends no farther than this. Their lives are lived in the world of appearances, and the idea of a more objective reality has no meaning.

But once we come to recognize the distinction between appearance and reality and the existence of objective factual or practical truth that goes beyond what perception, appetite and emotion tell us, the ability of creatures like us to arrive at such truth, or even to think about it, requires explanation.

The problem has two aspects. The first concerns the likelihood that the process of natural selection should have generated creatures with the capacity to discover by reason the truth about a reality that extends vastly beyond initial appearances–as we take ourselves to have done and to continue to do collectively in science…The second problem is the difficulty of understanding naturalistically the faculty of reason that is the essence of these activities.

But whenever we take such a reasonable detached attitude toward our innate dispositions, we are implicitly engaged in a form of thought to which we do not at the same time take that detached attitude. When we rely on systems of measurement to correct perception, or probability calculations to correct intuitive expectations, or moral or prudential reasoning to correct instinctive impulses, we take ourselves to be responding to systematic reasons which in themselves justify our conclusions, and which do not get their authority from their biological organisms. They could not be backed up in that way.

In the perceptual case I can recognize that I might be mistaken, but on reflection, even if I think of myself as the product of Darwinian natural selection, I am nevertheless justified in believing the evidence of my senses for the most part, because this is consistent with the hypothesis that an accurate representation of the world around me results from senses shaped by evolution to serve that function. That is not a refutation of radical skepticism, since evolutionary theory, like all of science, depends on the evidence of the senses.

This is the second problem: What is the faculty that enables us to escape from the world of appearance presented by our prereflective innate dispositions, into the world of objective reality? And what, besides consciousness, do we have to add to the biological story to make sense of such a faculty?

Perception connects us with the truth only indirectly. When I see a tree, I see it because it is there, but not just because it is there. Perception is not a form of insight: I do not grasp the presence of the tree immediately, even though it may seems so prior to reflection. Rather I am aware of it because the tree causes a mental effect in me in virtue of the character of my visual system, which we may suppose has been shaped by natural selection to react in this way to light reflected from physical objects. Having such a system together with other perceptual and motivational dispositions enables me to survive in the world. So it is only in a complicated and indirect sense that when I see a tree, I see it because it is there

Mind and Cosmos (Oxford 2012), 73-74,79-80, 82.

i) Nagel is rehearsing an ancient philosophical conundrum: the hiatus between appearance and reality. And even though he’s aware of the difficulty, he understates the difficulty. Having said “I am nevertheless justified in believing the evidence of my senses for the most part, because this is consistent with the hypothesis that an accurate representation of the world around me results from senses shaped by evolution to serve that function,” he admits that this “is not a refutation of radical skepticism, since evolutionary theory, like all of science, depends on the evidence of the senses.” So his appeal is circular.

ii) In addition, when he appeals to “senses shaped by evolution to serve that function,” that is contrary to naturalistic evolution. He’s offering a teleological description, but if naturalistic evolution is true, then evolution didn’t shape our senses to serve any function.

Quine has made similar observations. For instance:

It would address the question of how we, physical denizens of the physical world, can have projected our scientific theory of that whole world from our meager contacts with it; from the mere impacts of rays and particles on our surfaces and a few odds and ends such as the strain of walking uphill. From Stimulus to Science (Harvard 1999), ibid. 16.

There is a puzzle here. Global stimuli are private: each is a temporally ordered set of some one individual’s receptors. Their perceptual similarity, in part innate and in part modeled by experience, is private as well. Whence then this coordination of behavior across the tribe? ibid. 20.

The sensory atomist was motivated, I say, by his appreciation that any information about the world is channeled to us through the sensory surfaces of our bodies; but this motivation remained obscure to him. It was obscured by his concern to justify our knowledge of the external world. The justification would be vitiated by circularity if sensory surfaces and external impacts on nerve endings had to be appealed to at the outset of the justification. Confessions of a Confirmed Extensionist and Other Essays (Harvard 2008), 328.

There is much clarity to be gained by dropping the project of justifying our knowledge of the external world but continuing to investigate the relation of that knowledge to its sensory evidence. Obscurity about the nature of the given, or epistemic priority, is then dissipated by talking frankly of the triggering of nerve endings. We then find ourselves engaged in an internal question within the framework of natural science. There are these impacts of molecules and light rays upon our sensory receptors, and there is all this output on our part of scientific discourse about sticks, stones, planets, numbers, molecules, light rays, and, indeed, sensory receptors; and then we pose the problem of linking that input causally and logically to that output, ibid. 328.

Much as I admire [David] Lewis’s reduction, however, it is not for me. My own line is a yet more sweeping structuralism, applying to concrete and abstract objects indiscriminately. I base it, paradoxically as this may seem, on a naturalistic approach to epistemology. Natural science tells us that our ongoing cognitive access to the world around us is limited to meager channels. There is the triggering of our sensory receptors by the impact of molecules and light rays. Also there is the difference in muscular effort sensed in walking up or down hill. What more? Even the notion of a cat, let alone a class or number, is a human artifact, rooted in innate predisposition and cultural tradition. The very notion of an object at all, concrete or abstract, is a human contribution, a feature of our inherited apparatus for organizing the amorphous welter of neural input, ibid. 402-03.

The conclusion is that there can be no evidence for one ontology as over against another, so long anyway as we can express a one-to-one correlation between them. Save the structure and you save all. Certainly we are dependent on a familiar ontology of middle-sized bodies for the inception of reification, on the part both of the individual and of the race; but once we have an ontology, we can change it with impunity, ibid, 405.

This global ontological structuralism may seem abruptly at odds with realism, let alone naturalism. It would seem even to undermine the ground on which I rested it: my talk of impacts of light rays and molecules on nerve endings. Are these rays, molecules, and nerve endings themselves not disqualified now as mere figments of an empty structure? ibid. 405.

Naturalism itself is what saves the situation. Naturalism looks only to natural science, however, fallible, for an account of what there is and what what there is does. Science ventures its tentative answers in man-made concepts, perforce, couched in man-made language, but we can ask no better. The very notion of object, or of one and many, is indeed as parochially human as the parts of speech; to ask what reality is really like, however, apart from human categories, is self-stultifying. It is like asking how long the Nile really is, apart from parochial matters of miles or meters. Positivists were right in branding such metaphysics as meaningless, ibid. 405.

So far as evidence goes, then, our ontology is neutral. Nor let us imagine beyond it some inaccessible reality. The very terms ‘thing’ and ‘exist’ and ‘real,’ after all, make no sense apart from human conceptualization. Asking after the thing in itself apart from human conceptualization, is like asking how long the Nile really is, apart from our parochial miles or kilometers. ibid, 416.

So it seems best for present purposes to construe the subject’s stimulus on a given occasion simply as his global neural intake on that occasion. But I shall refer to it only as neural intake, not stimulus, for other notions of stimulus are wanted in other studies, particularly where different subjects are to get the same stimulus. Neural intake is private, for subjects do not share receptors, ibid. 463-64.

But in contrast to the privacy of neural intakes, and the privacy of their perceptual similarity, observation sentences and their semantics are a public matter, since the child has to learn these from her elders. Her learning then depends indeed both on the public currency of the observation sentences and on a preestablished harmony of people’s private scales of perceptual similarity, ibid. 464.

These reflections on ontology are a salutary reminder that the ultimate data of science are limited to our neural intake, and that the very notion of object, concrete or abstract, is of our own making, along with the rest of natural science and mathematics, ibid. 471.

i) That’s the dilemma. How does the mind escape the world of appearances to come into contact with objective reality? How does appearance map onto reality?

ii) Science tries to present an objective, third-person description of the world. But science must rely on the subjective, first-person viewpoint of the human observer. How can science bootstrap an objective understanding from the “meager input” of our sensory receptors? How can science reliably extrapolate from “impacts of light rays and molecules on our sensory surfaces or nerve endings” to a global depiction of the outside world? Indeed, even talk of nerve endings and sensory receptors depends on the realm of appearance. On how our body appears to us. For instance, we have to use our eyes to see our eyes. If we see our eyes through our eyes, what are we really looking at? So the appeal is circular.

At this level we can’t directly appeal to other observers to corroborate our own perceptions, for they are in the same boat–and, in any case, our knowledge of other observers is filtered through our own perceptions.

iii) Here is where transcendental theism can break into the circle. Let’s begin by defining a transcendental argument:

As standardly conceived, transcendental arguments are taken to be distinctive in involving a certain sort of claim, namely that X is a necessary condition for the possibility of Y—where then, given that Y is the case, it logically follows that X must be the case too.

http://plato.stanford.edu/entries/transcendental-arguments/

iv) So, for instance, if God designed our sensory perceptual system, and if that’s preadapted to our physical environment, which God also designed, then our senses are generally reliable to perform what they were designed to do.

v) That, itself, is a fairly modest claim. It doesn’t tell you in advance what they were designed to do. It doesn’t specify the scope of their reliability. In principle, this is consistent with anything from direct realism through indirect realism and phenomenalism to idealism.

vi) It does, however, ground the reliability of sensory perception in a way that atheism cannot. The senses are trustworthy when we use them to do whatever they were designed to do.

vii) That’s an argument from creation and providence. But there’s also an argument from revelation. If the Bible is divine revelation, then there’s a sense in which the Bible gives us a second pair of eyes. A God’s-eye view of the world. God’s knowledge of the world doesn’t arise from the world of the senses.

We can’t get outside ourselves. We can’t access the world behind the senses. But God’s viewpoint is truly external.

viii) Of course, God speaks to us in sensory language. Revealed truths assume an analogy between appearance and reality. They overlap at the relevant point of comparison. Even if our mental representation of the world were a metaphor, metaphors convey knowledge.

Indeed, God created that analogical correspondence. That’s why he can use this medium to reveal truths about the physical world, truths about history, truths about the past and the future. 

ix) Now this kind of argument admittedly has a limitation. Transcendental arguments must begin from some starting-point or another. If an atheist rejects the starting-point, then the argument will be ineffective. If we grant Y, and X is a necessary condition of Y, then that commits us to X–but what if we don’t grant the premise?

x) So this has the limitations of any conditional or hypothetical argument. But that doesn’t make it a flawed argument. Persuasion is not the only aim of argumentation. We may use an argument to expose the cost of atheism. What price is the atheist prepared to pay to maintain his atheism? Will he commit intellectual suicide?

We’re pushing the atheist. Pushing him to the ledge. We can’t stop him from jumping, but that will betray the defiant irrationality of the atheist. In order to deny God, he must deny himself. The price of hating God is self-hatred. 

xi) This also has implications for the relationship between philosophy and theology, general and special revelation. On one model, special revelation is subordinate to general revelation. You must begin with general revelation. And that, in turn, will adjudicate special revelatory claimants.

But on the model I’m proposing, we need special revelation to ratify our knowledge of the external world. Appeal to general revelation assumes the reliability of sensory perception (as well as reason and memory). But unless God vouches for sense knowledge, unless we have that external check on our private perceptions, there’s no overriding reason to trust our senses.

So the relationship between general and special revelation is dialectical. Mutually validating. Without general revelation, special revelation is blind; without special revelation, general revelation is lost.

Consider psychotics. They may have acute hearing and 20/20 vision. But it makes no difference, for they are trapped in the prison of the mind.

To be lost inside your own mind is far more terrifying than if you lose your way in the woods. In a godless world, that’s our fate.