Can you imagine an A380 flying backwards? Of course you can. Just imagine a large plane in the air, moving backwards. Is such a scenario really conceivable? Well, the more you know about aerodynamics and aeronautical engineering, the less conceivable it becomes. It just cannot be done.
Seth follows this up with a knock-down argument against Chalmers’ philosophical zombies:
In one sense it’s trivial to imagine a philosophical zombie. I just picture a version of myself wandering around without having any conscious experiences. But can I really conceive this? What I’m being asked to do, really, is to consider the capabilities and limitations of a vast network of many billions of neurons and gazillions of synapses (the connections between neurons), not to mention glial cells and neurotransmitter gradients and other such neurobiological goodies, all wrapped into a body interacting with a world which includes other brains in other bodies. Can I do this? Can anyone do this? I doubt it.
That’s a disanalogous analogy. In the first case, we cant imagine the plane flying backwards in terms of our knowledge of aerodynamics, because aerodynamics makes it impossible; in the second case, we don’t have a theory that makes it inevitable that neural activity must be accompanied by phenomenal consciousness—such a theory would be an answer to the hard problem.
That’s a disanalogous analogy. In the first case, we cant imagine the plane flying backwards in terms of our knowledge of aerodynamics, because aerodynamics makes it impossible; in the second case, we don’t have a theory that makes it inevitable that neural activity must be accompanied by phenomenal consciousness—such a theory would be an answer to the hard problem.