Consciousness exists, but not independently of behaviour and behavioural disposition, which can be studied through heterophenomenology. The origin of this operationalist approach can be found in Dennett's immediately preceding work. Dennett (1988) explains consciousness in terms of "access consciousness" alone, denying the independent existence of what Ned Block has labeled "phenomenal consciousness". He argues that "Everything real has properties, and since I don't deny the reality of conscious experience, I grant that conscious experience has properties". Having related all consciousness to properties, he concludes that they cannot be meaningfully distinguished from our judgements about them. He writes:  In other words, once we've explained a perception fully in terms of how it affects us, there is nothing left to explain. In particular, there is no such thing as a perception which may be considered in and of itself (a quale). Instead, the subject's honest reports of how things seem to them are inherently authoritative on how things seem to them, but not on the matter of how things actually are. The key to the multiple drafts model is that, after removing qualia, explaining consciousness boils down to explaining the behaviour we recognise as conscious. Consciousness is as consciousness does. Some of the criticism of Dennett's theory is due to the perceived tone of his presentation. As one grudging supporter admits, "there is much in this book that is disputable. And Dennett is at times aggravatingly smug and confident about the merits of his arguments ... All in all Dennett's book is annoying, frustrating, insightful, provocative and above all annoying" (Korb 1993). Bogen (1992) points out that the brain is bilaterally symmetrical. That being the case, if Cartesian materialism is true, there might be "two" Cartesian theatres, so arguments against only one are flawed. Velmans (1992) argues that the phi effect and the cutaneous rabbit illusion demonstrate that there is a delay whilst modelling occurs and that this delay was discovered by Libet. It has also been claimed that the argument in the multiple drafts model does not support its conclusion. Much of the criticism asserts that Dennett's theory attacks the wrong target, failing to explain what it claims to. Chalmers (1996) maintains that Dennett has produced no more than a theory of how subjects report events. Some even parody the title of the book as "Consciousness Explained Away", accusing him of greedy reductionism. Another line of criticism disputes the accuracy of Dennett's characterisations of existing theories: Multiple drafts is also attacked for making a claim to novelty.