I'm afraid I can't see where you demonstrate the incoherence of the hypothesis or address the points I raised. Nor do I understand why you can't define consciousness to some extent by virtue of being conscious. I can see your objection to the hypothesis that zombies are without consciousness - that we can't specify exactly and completely what it is they're without - but as this objection would apply equally to the the hypothesis that human beings are endowed with consciousness, (we can't specify what it is they're endowed with), it seems to have tragic ramifications for consiousness studies. I'd rather call it a proviso than an objection. The difficulty of defining consciousness is not made any easier to overcome if we're not allowed to wonder what we have that a zombie does not have, in my opinion, but no matter, we'll just have to disagree. Thanks for the joust. PJ