“Probably most professional philosophers in the field would hold that given your body, the state of your brain, and your specific environment, you could not act differently from the way you’re acting now—that your actions are preordained, as it were. Imagine that we could produce a perfect duplicate of you, a functionally identical twin who is an exact copy of your molecular structure. If we were to put your twin in exactly the same situation you’re in right now, with exactly the same sensory stimuli impinging on him or her, then initially the twin could not act differently from the way you’re acting. This is a widely shared view: It is, simply, the scientific worldview. The current state of the physical universe always determines the next state of the universe, and your brain is a part of this universe.”

“The phenomenal Ego, the experiential content of the human self-model, clearly disagrees with the scientific worldview—and with the widely shared opinion that your functionally identical doppelgänger could not have acted otherwise. If we take our own phenomenology seriously, we clearly experience ourselves as beings that can initiate new causal chains out of the blue—as beings that could have acted otherwise given exactly the same situation. The unsettling point about modern philosophy of mind and the cognitive neuroscience of will, already apparent even at this early stage, is that a final theory may contradict the way we have been subjectively experiencing ourselves for millennia. There will likely be a conflict between the scientific view of the acting self and the phenomenal narrative, the subjective story our brains tell us about what happens when we decide to act.”

— Thomas Metzinger, The Ego Tunnel

Thomas Metzinger, The Ego Tunnel