The most basic debate over consciousness in this sense is whether it can be explained in physical terms, or is in principle inexplicable in physical terms. David Chalmers, a leading advocate of the second view, defends his position primarily by appealing to the possibility of a physical duplicate of a person without any of that person's subjective experiences (the zombie argument) or the possibility of a super-scientist who knows everything about the physical aspects of perception but doesn't know what it's like to have a particular experience (the knowledge argument, or "Mary" argument for the name commonly given to the hypothetical super-scientist). John Searle has accused proponents of the physical view of consciousness of simply ignoring our conscious experiences. In response, Daniel Dennett has argued that the anti-physicalist position makes consciousness something utterly mysterious, which our scientific investigations into the brain have inexplicably failed to detect. Against the accusation that he is denying something obvious which we could not be mistaken about, Dennet has said "this is a mysterious doctrine (at least as mysterious as papal infallibility)." In order to make their views comfortable with modern science, many proponents of physically irreducible consciousness endorse a view known as epiphenomenalism, which says that conscious states are caused by the brain but do not themselves cause anything physical. In the view of critics like Dennett, however, this simply contributes to the mysteriousness of the view.
Neurological Background Information
The organ by which we come about perceiving our world and make sense of it is the brain.
The center of cognition in the human brain is the frontal lobe, which is in addition used for executive function - i.e. pulling together information and deciding what to do with it.
Sensory perception is located in the parietal and temporal lobes; disorders which afflict this particular area include temporal lobe epilepsy, a noted subject of neurotheology (for more information, read the works of neurotheologists Richard Davidson and Robert Persinger).
The limbic system, especially the hypothalamus and amygdala, pull together and react to this information to send it to the frontal lobes. Swedish neuroscientist Bjorn Merker has in addition postulated that the brain stem produces a rudimentary consciousness which includes perception, integration, decision, and action on external stimuli. This perception and cognition and the action of executive function and the hypothalamus combine to create thought.
The Argument to God
Many theistic apologists have claimed that the existence of non-physical consciousness proves the existence of God. However, this is by no means obvious. In contemporary philosophy, the most prominent defenders of non-physical consciousness are atheists. This is true of both John Searle and David Chalmers. Other examples of nontheistic philosophers who reject the physicalist view of consciousness are Thomas Nagel and Paul Draper. At the popular level this view has been promoted by Sam Harris.
What theists need is an argument that consciousness is evidence for the existence of God, but they rarely bother to try to give such an argument. Stewart Goetz and Charles Taliaferro have claimed to present such an argument, but they seem to be stuck in the same confusions as other theists. For example, they talk about "restrict[ing] ourselves... to the explanatory framework of an ideal physics with mass and energy," which misses the point, because this is not the approach taken by philosophers such as Chalmers. Rather, Chalmers postulates something apart something from the physical world connected to it by laws broadly similar to the laws of physics.
More broadly, unless one takes the view that the mental could only be related to the physical by constant divine intervention (a position which has not been historically popular), it seems theists and atheists are in the same situation with respect to explaining consciousness. What's needed is an account of how consciousness works, and it doesn't matter if the system was set up by God or is a brute fact about the universe. Assertions that the "brute fact" response is unacceptable will ultimately fall back on the reasoning behind the cosmological and design arguments. If these arguments fail, there is no reason to think the argument from consciousness would do any better, and even if they succeeded, there is no reason to think consciousness would reinforce them.
- Daniel C. Dennett, Consciousness Explained
- David Chalmers, The Conscious Mind
- John Searle, The Mystery of Consciousness
- Quining Qualia by Daniel C. Dennett
- God or Blind Nature? Philosophers Debate the Evidence by Paul Draper