When you read about the theological questions that led Christians to kill and excommunicate one another, "angels dancing on the head of a pin" is not far off. The Homoousion, Monophysitism, the Filioque controversy... It's all so arcane and poorly defined. It almost makes one wish Positivism had been invented 2000 years earlier.
The current AI debate about consciousness does remind me of that in one respect: no one can even clearly define what consciousness is.