And yet no one has ever seriously claimed that clouds are an illusion. I don't understand this need that behaviorists have to not just set the inner life aside

And yet no one has ever seriously claimed that clouds are an illusion. I don't understand this need that behaviorists have to not just set the inner life aside but to claim that it doesn't even exist. It clearly does. It's the one thing each of us knows with utmost certainty. Just because there might be an explanation for it based on more fundamental principles—principles which, I might add, we are nowhere near understanding—doesn't mean it's not real.