Actually there are people who believe that a calculator is "thinking" just a tiny bit, and that LLMs are thinking a bit more.
To believe that a human is thinking, you have to find the demarcation between a brain and a neuron. Then between a neuron and a cell. Then between a cell and a protein. Then between a protein and a molecule.
Alas, I cannot even prove there is any conscious being in the universe at all besides myself. Obviously proof is the goal, but our existing "self-evidently true" understanding of this problem space also has effectively zero proven foundation.
Proof isn't the goal here. Centuries of thought and experimentation have made it clear that we currently have no ability to decisively determine whether something is conscious.
However, as humans we intuitively build projections of what we believe is the internal world of other beings. We also clearly believe there is a continuum of complexity of thought among all the beings that we have observed.
The question then becomes, what behaviors of computer programs match up with what we consider conscious behaviors of other beings we have observed? This is a necessary question because we don't have access into the internal states of others, so we have to interrogate the full complexity of what we believe represents consciousness, and whether these beings match those behaviors.
