The mind and God have this in common: They are both things that cannot be known directly through something like scientific investigation. If they are known at all, then they are known through modes that transcend science; they are known philosophically. I wonder if this is why modern atheism, which tends to be driven by a restriction of knowledge to the empirical sciences, tends to end up denying the mind as well as God.
Let us take the mind first. The nature of the mind is to be a knower or comprehender of the world. When the scientist takes the mind as an object for his investigation, he necessarily turns the mind into an object in the world comprehended by his own mind. Therefore, in the very exercise of his science, he manifests a mind that must transcend the nature of whatever mind he concludes from science. The mind he investigates through science - "mind as object in the world of science" - is only a pale replica of the true mind - "mind as comprehender and judge of science." Therefore science can never fully fathom the mind, as science itself testifies in its very exercise.
One of the joys of philosophy is that one can know eternal and immutable truths through it, truths that are more certainly known than scientific truths, not less. The fact that the scientist, in the conduct of his science, manifests a mind that transcends the mind as it appears as an object of science, is one of these eternal and immutable truths. It must happen with iron metaphysical necessity, just as a body, when it moves to there, must depart from here. Yet many scientific and philosophical practitioners of the investigation of the mind fail to understand this point. They think a comprehensive account of the mind is available to science, at least in principle. And when they fail to discover any immaterial, world-knowing mind through science, they dismiss it as a myth concocted by the ignorant past.
The unintentional irony of all such efforts, of course, is that they manifest the world-knowing transcendent mind in the very act of denouncing it. They must do so. The fun in reading such works is finding the moment when the investigator performs an act of the mind denied by his science. Take for example, V.S. Ramachandran in A Brief Tour of Human Consciousness. This is a fascinating work of popular neuroscience in which we get scientific explanations of everything from phantom limbs to the purple numbers of the book's subtitle. But then Ramachandran sums up his research this way:
"Our brains are essentially model-making machines. We need to construct useful, virtual reality simulations of the world that we can act on."
Now this may be a true statement in the scientific sense, that is, as pertaining to minds as they appear as objects before neuroscience. But it can't be true of Ramachandran's mind as the comprehender of neuroscience. Or, if it is, then the statement means something other than what Ramachandran apparently means by it. For if brains are essentially model-makers, and this includes Ramachandran's scientific brain as well as his subject's, then neuroscience isn't really about the brain at all. It's about the virtual reality simulations scientists make of a reality that is in itself as unknowable to scientists as it is to the rest of us; for scientists have no way of stepping outside their own model-making minds and comparing the models to reality. Not only couldn't we know if our models of brains accurately represent real brains, but we couldn't know whether reality actually had anything in it corresponding to "brains" at all. But, of course, there is an implicit exemption in Ramachadran's statement, for he obviously intends the statement to be about what brains are really like, not merely about his personal virtual reality simulation. And if the statement is about real brains, then not every brain can be merely a model-maker; in particular, Ramachandran's can't be.
Another example can be found in the work of neuroscientist Antonio Damasio:
"These various images - perceptual, recalled from the real past, and recalled from plans of the future - are constructions of your organism's brain. All that you can know for certain is that they are real to your self, and that other beings make comparable images. We share our image-based concept of the world with other humans, and even with some animals; there is a remarkable consistency in the constructions different individuals make of the essential aspects of environment (textures, sounds, shapes, colors, space). If our organisms were designed differently, the constructions we make of the world around us would be different as well. We do not know, and it is improbable that we will ever know, what "absolute reality" is like."
Well, if we can't know what absolute reality is like, then all that Damasio has just written is not about reality, but only a construction he has made about a reality that is in itself unknowable. And that includes constructions of what our minds can and cannot do. Damasio may write that all you can know for certain is that images are real to yourself, but that statement is but a construction he puts on reality; reality may be that my mind really can go beyond images to the real nature of things. In fact, if Damasio intends his writing to be about what brains and minds are really like, which seems clear, then the human mind must be capable of knowing more than merely its own images.
Immanuel Kant thoroughly explored the logic of this kind of thinking a few centuries ago in the Critique of Pure Reason. If you wish to understand the meaning of the contemporary investigation of the mind, Kant is the philosopher to read, for he understood the meaning of any possible empirical science of the mind long before they began to be practiced. Like many thinkers today, Kant held that the positive sciences are the only way of knowing empirical reality. But he also understood that the positive sciences are creative products of the mind of man; man creates science in order to force nature to explain itself in categories amenable to his understanding. The science-creating and science-judging mind is therefore invisible to the science it creates, because it is always behind the science as its ground and never in front of it as an object. The scientist who tries to "get behind" the mind through science is like the man who thinks he can get behind his own shadow by stepping over it.
This isn't to say that the empirical investigation of the mind is without value; far from it. But it is to say that the empirically known mind is necessarily less than the full story of the mind. The full story can only be known by a philosophy that acknowledges that the empirical sciences do not exhaust our ways of knowing empirical reality. The realist philosophy of St. Thomas Aquinas is such a philosophy.
The Thomist philosopher, in contrast to the scientist, does not attempt to understand the mind as an external object on which he can perform tests and experiments. Instead, he attempts to understand his own act of knowing in the very act of knowing. St. Thomas calls this the "intellect knowing itself through itself." This is not a paradoxical, mind-boggling or anti-scientific concept. It simply means that the philosopher reflects on what happens to himself when he goes from a state of ignorance to knowledge. Since it is the mind reflecting on its own act, this is the mind knowing itself through itself. It is the mind knowing itself as "a knower and comprehender of the world", not as "an object for science" that implies a transcendent mind lurking in the background.
A consequence of the Thomistic approach is that the philosopher cannot produce a "theory of the mind" so beloved by empirical scientists, one that would permit anyone to know the mind simply by reading a result out of a book. The best the philosopher of mind can do is aid other minds in coming to know the way he as come to know; that is, in coming to know their own minds through themselves. This is, in fact, the rule of Socratic midwifery that holds for philosophy in general.
Part II of this thread can be found here.