> Science is better then this. We don't need to directly observe something, it's OK to be able to just indirectly observe. Indirect observations involve formin

> Science is better then this. We don't need to directly observe something, it's OK to be able to just indirectly observe. Indirect observations involve forming a testable (and falsifiable) hypothesis. What you're doing above is more like an attempt at proof by contradiction... But I can assume the contrary viewpoint and deduce as well. Suppose human consciousness is non-physical. From observation (as you said) we know it can be affected by physical things -- brain damage, drugs, etc. So it must have a physical/nonphysical interface, probably in our brains. You might say Occam's razor rules non-physicality out, since such an interface is a bit much to assume. But given that we don't have a meaningful way forward assuming physical-only, perhaps admitting one further assumption can help our inquiry - perhaps physical-only is too simple an explanation. As Einstein said, "Everything should be made as simple as possible, but not simpler."