This is silly. It's the sum of electrical and chemical network activity in the brain. There's nothing else it can be. We've got a good enough handle on physics to know that it's not some weird quantum thing, it's not picking up radio signals from some other dimension, and it's not some sort of spirit or mystical phlogiston.
Your mind is the state of your brain as it processes information. It's a computer, in the sense that anything that processes information is a computer. It's not much like silicon chips or the synthetic computers we build, as far as specific implementation details go.
There's no scientific evidence that anything more is needed to explain everything the mind and brain does. Electrical and chemical signaling activity is sufficient. We can induce emotions, sights, sounds, smells, memories, moods, pleasure, pain, and anything you can experience through targeted stimulation of neurons in the brain. The scale of our experiments has been gross, only able to read and write from large numbers of neurons, but all the evidence is consistent.
There's not a single rigorously documented phenomenon, experiment, or any data in existence that suggests anything more than electrical and chemical signaling is needed to explain the full and wonderful and awe-inspiring phenomenon of the human mind.
It's the brain. We are self constructing software running on 2lb chunks of fancy electric meat stored in a bone vat with a sophisticated network of sensors and actuators in a wonderful biomechanical mobility platform that empowers us to interact with the world.
It explains consciousness, intelligence, qualia, and every other facet and nuance of the phenomena of mind - there's no need to tack on other explanations. It'd be like insisting that gasoline also requires the rage of fire spirits in order to ignite and power combustion engines - once you get to the point of understanding chemical combustion and expansion of gases and transfer of force, you don't need the fire spirits. They don't bring anything to the table. The scientific explanation is sufficient.
Neocortical networks, with thalamic and hippocampal system integrations, are sufficient to explain the entirety of human experience, in principle. We don't need fire spirits animating cortical stacks, or phlogiston or ether or spirit.
Could spirit exist as a distinct, separate phenomenon? Sure. It's not intrinsic to subjective experience, consciousness, and biological intelligence, though, and we should use tools of rational thinking when approaching these subjects, because a whole lot of pseudo-scientific BS gets passed as legitimate scientific and philosophical discourse without having any firm grounding in reality.
We are brains in bone vats - nothing says otherwise. Unless or until there's evidence to the contrary, let that be enough.
I think you misunderstood the person you're responding to. They did not say there was some higher force beyond the physical pieces.
What they're saying is that the brain is really really complicated and our understanding of biology is far too rudimentary right now to be saying "yes, absolutely, 100% sure that we know the nature of consciousness from this one measurement of one type of signal".
* Neurons are very complex and all have unique mutations from one another
* Hundreds of other types of cells in the brain interact with them and each other in ways we don't understand
* The various other parts of the body chemically interact with the brain in ways we don't understand yet, like the gut microbiome
Trying to flatten all of consciousness to one measurement is just not sufficient. It's like trying to simulate the entire planet as a perfect sphere of uniform density. That works OK for some things but falls apart for more complex questions.