Of course there is a dependency consciousness has on our physical brain. There is no arguing that. A car cannot function without a working engine, but that doesn't mean it doesn't require a driver to operate it. In other words, our brain (car engine) needs to be functional for us to drive, but the driver (soul) is also required... we just can see or measure it.
Let me pursue your analogy.
Imagine that we have some cars and some unobservable drivers. How could we tell that these unobservable drivers exist?
- Observe something in the car that violates established laws of physics (e.g. the gas pedal lowers on its own)
- Observe that two physically identical cars behave differently (e.g. both cars start out in park, one drives off obeying traffic laws, while the other drives aimlessly into things, or just sits there in park; perhaps one driver is more skilled than the other)
- Observe that the 'intentions' of the car cannot be altered by physically changing the car (e.g. no matter how you play with the engine or brakes, the driver will still do his best to avoid running into a crowd of people)
Any of these observations would falsify the hypothesis that the behavior of cars is exclusively the result of physical causes. The same argument could be made for any physical system, including brains, both animal and human.
We could add a fourth observation in the case of a brain or machine capable of communicating its experience or at least exhibiting signs of unique experiences:
4. Observe that the experiences indicated by the behavior of the machine (e.g. it says 'I see the color blue', or its feelings/experiences are evident by its behavior) do not correspond to anything physical about the machine.
Despite a wealth of research, none of these observations have been made with respect to any physical system that I know of, even human brains. Clearly, human brains, chimpanzee brains, and cell phones are not inhabited by these sorts of supernatural 'drivers'.
Now, you could postulate some things about the human 'soul' that makes it different from the supernatural 'drivers' above:
- Maybe we just haven't found the part of the brain where a non-physical action occurs; or, maybe the soul is actually a passive 'receiver' who doesn't interact with the brain but who experiences what it's like to be sitting in it nonetheless.
- Maybe souls are too similar to be distinguished by the different ways in which they control brains; also, maybe brains with certain physical characteristics are always inhabited by a soul.
....and so on. I have no doubt that, if we try hard enough, we can make all sorts of ad-hoc hypotheses about the human soul in order to make it immune to empirical falsification.
However,
I am equally certain that we could postulate an unfalsifiable soul for the chimpanzee brain, cell phones, or any physical system. So why should we take the existence of an unfalsifiable human soul more seriously than the existence of an unfalsifiable cell phone soul?
Nick Soapdish said:
This to me seems to be the most reasonable solution, since the physical brain cannot account for our entire "mind" experience. Something else is missing besides what we can measure.
You have not 'solved' anything simply by observing that we don't understand something and declaring the existence of a supernatural soul. To call this a 'solution' is a pretty big stretch, unless you can use it to predict
something (e.g. you could predict the four observations I outlined above).