Ok, so let's say I put two different systems in front of you, and I tell you that system A is conscious whereas system B is not. Based on this knowledge, can you make any meaningful predictions about the differences in behavior between the two systems ? As far as I can tell, the answer is "no". Here are some possible differences that people have proposed over the years:

• Perhaps system A would be a much better conversation partner than system B. But no, System B could just be really good at pretending that it's conscious, without exhibiting any true consciousness at all.

• System A will perform better at a variety of cognitive tasks. But no, that's intelligence, not consciousness, and in fact system B might be a lot smarter than A.

• System A deserves moral consideration, whereas system B is just a tool. Ok, but I asked you for a prediction, not a prescription.

It is quite possible that I'm missing something; but if I'm not, then consciousness is an empty concept, since it has no effect on anything we can actually observe.