resides in the whole body. (Bergson, 1911) There has been a lively debate about what the zombie argument shows. Critics who primarily argue that zombies are not conceivable include Daniel Dennett, Nigel J. T. Thomas, David Braddon-Mitchell, and Robert Kirk; critics who assert mostly that conceivability does not entail possibility include Katalin Balog, Keith Frankish, Christopher Hill, and Stephen Yablo; and critics who question the logical validity of the argument include George Bealer. In his 2019 update to the article on philosophical zombies in the Stanford Encyclopedia of Philosophy, Kirk summed up the current state of the debate: A 2013 survey of professional philosophers conducted by Bourget and Chalmers produced the following results: In 2020, the same survey yielded "inconceivable" 16%, "conceivable but not possible" 37%, "metaphysically possible" 24%, and "other" 23%. Types of zombies Though philosophical zombies are widely used in thought experiments, the detailed articulation of the concept is not always the same. P-zombies were introduced primarily to argue against specific types of physicalism such as behaviorism, according to which mental states exist solely as behavior. Belief, desire, thought, consciousness, and so on, are only behavior (whether external behavior or internal behavior) or tendencies towards behaviors. A p-zombie that is behaviorally indistinguishable from a normal human being but lacks conscious experiences is therefore not logically possible according to the behaviorist, so an appeal to the logical possibility of a p-zombie furnishes an argument that behaviorism is false. Proponents of zombie arguments generally accept that p-zombies are not physically possible, while opponents necessarily deny that they are metaphysically or, in some cases, even logically possible. The unifying idea of the zombie is that of a human completely lacking conscious experience. It is possible to distinguish various zombie sub-types used in different thought experiments as follows: A behavioral zombie that is behaviorally indistinguishable from a human. A neurological zombie that has a human brain and is generally physiologically indistinguishable from a human. A soulless zombie that lacks a soul. An imperfect zombie or imp-zombie that is like a p-zombie but has slightly different behavior than a regular human. They are important in the context of the mind-evolution problem. A zombie universe that is identical to our world in all physical ways, except no being in that world has qualia. Zombie arguments Zombie arguments often support lines of reasoning that aim to show that zombies are metaphysically possible in order to