What makes something a mind might have nothing to do with what it's made of
Functionalism argues that a mental state like pain isn't defined by any particular stuff, neurons or silicon, but by what it does: what causes it and what it causes in turn. Hilary Putnam argued an octopus, a human and, in principle, a machine could all genuinely feel pain despite sharing no physical material, so long as something in each system plays pain's same functional role. The idea underpins most modern arguments for the possibility of a truly thinking machine.