have second-order beliefs – to argue that the idea of a p-zombie is incoherent; "Zimboes thinkZ they are conscious, thinkZ they have qualia, thinkZ they suffer pains – they are just 'wrong' (according to this lamentable tradition), in ways that neither they nor we could ever discover!". Michael Lynch agrees with Dennett, arguing that the zombie conceivability argument forces us to either question whether or not we actually have consciousness or accept that zombies are not possible. If zombies falsely believe they are conscious, how can we be sure we are not zombies? We may believe we are experiencing conscious mental states when, in fact, we merely hold a false belief. Lynch thinks denying the possibility of zombies is more reasonable than questioning our own consciousness. Furthermore, when concept of self is deemed to correspond to physical reality alone (reductive physicalism), philosophical zombies are denied by definition. When a distinction is made in one's mind between a hypothetical zombie and oneself (assumed not to be a zombie), the hypothetical zombie, being a subset of the concept of oneself, must entail a deficit in observables (cognitive systems), a "seductive error" contradicting the original definition of a zombie. Thomas Metzinger dismisses the argument as no longer relevant to the consciousness community, calling it a weak argument that covertly relies on the difficulty in defining "consciousness", calling it an "ill-defined folk psychological umbrella term". Verificationism states that, for words to have meaning, their use must be open to public verification. Since it is assumed that we can talk about our qualia, the existence of zombies is impossible. Artificial intelligence researcher Marvin Minsky saw the argument as circular. The proposition of the possibility of something physically identical to a human but without subjective experience assumes that the physical characteristics of humans are not what produces those experiences, which is exactly what the argument was claiming to prove. Richard Brown agrees that the zombie argument is circular. To show this, he proposes "", which are creatures nonphysically identical to people in every way and lacking phenomenal consciousness. If existed, they would refute dualism because they would show that consciousness is not nonphysical, i.e., is physical. Paralleling the argument from Chalmers: It is conceivable that exist, so it is possible they exist, so dualism is false. Given the symmetry between the zombie and arguments, we cannot arbitrate the physicalism/dualism question a priori. Similarly, Gualtiero Piccinini argues