steveb1 wrote:That is, if as HH Dalai Lama says, Buddhism must embrace scientific truth, then how does Buddhism defend mind only from the apparent fact that brain causes mind?
The short answer: It doesn’t need to, as the evidence so far is non-contradictory.
The long answer: There is no universally accepted scientific definition of consciousness, nor agreement on whether consciousness has a specific neural correlate or is a product of the relationship of several. So, technically speaking Buddhism has not yet been given a specific theory to refute. There is no positive evidence that consciousness is solely
the product of the brain, and whether this hypothesis is even falsifiable (How do we isolate a brain? Is a synthetic brain even possible? How do we know a subject is conscious? Etc.) and thus a scientific hypothesis is still debated.
Physicalism and Eliminative Materialism in relation to the philosophy of mind are philosophical positions that posit a brain emergent theory of consciousness. As schools of philosophy, these should not be confused with scientific fact, or even close to it, even though these are probably accepted by the majority of scientists and often argued by them. Nevertheless, what the consensus is even on is not obvious. Even within emergent theories of mind there is disagreement, such as whether consciousness is emergent from the bio-chemical, the informational, the quantum or higher-level, non-reductive processes.
Despite this, many of these notions only appear to be “brain-only” on a superficial inspection. For example, if we assume physicalism is valid, consciousness would not be possible by most physicalist accounts without external, non-neural stimuli. That is, consciousness is dependent on a non-conscious sensory environment even then, and hence not literally solely neural in the first place.
Aside from all this, there are other philosophical issues with equating consciousness solely to brain activity, such as the "hard problem", the non-algorithmic nature of cognition, whether a “Turing-like” test is tenable etc.
So in short, consciousness as a property of the brain alone is a complex philosophical claim that lacks definition, is not a scientific fact nor even a true hypothesis so impossible to respond to directly. Despite the fact that it is the preferred position of scientists it is still a philosophical, non-testable claim without positive evidence. I can cite any of the above claims if necessary.
As for these “over-confident” types, they are still often honest with regard to actual scientific progress:
Hope this helps, sorry for the long post, but it is a fairly complex topic that’s difficult to summarise as I am sure you know.
P.S. “All is mind” in the purely phenomenological sense is in total agreement with modern perceptual theory, throughout the cognitive sciences.