Luca Malatesti

Boran Berčić, in the second volume of his recent book "Filozofija" , offers two responses to David Chalmers’s conceivability or modal argument against physicalism. This latter argument aims at showing that zombies, our physical duplicates who lack consciousness, are metaphysically possible, given that they are conceivable. Berčić’s first response is based on the principle of the uniformity of nature that states that causes of a certain type will always cause effects of the same type. His second response is based on the assumption that the basic statements of physicalism in philosophy of mind are or should be contingently true. I argue that if Berčić’s first defence is aimed at the conceivability of zombies, it is unsatisfactory. Moreover, I argue that a quite similar argument, offered by John Perry in his book "Knowledge, Possibility and Consciousness" , is afflicted by a similar problem. Nevertheless, under a more plausible interpretation, Berčić’s argument might be taken to attack the metaphysical possibility of zombies. This version of the argument might be effective and has the merit to point out a so far overlooked link between the discussion of the Chalmers’s conceivability arguments against physicalism and the modal strength of causal links and natural laws. Then, I argue that Berčić’s second defence of physicalism, which cannot be combined consistently with his first one, in any case, should not be formulated in the terms of contingent physicalism.

Frank Jackson’s knowledge argument (KA) aims to prove, by means of a thought experiment concerning the hypothetical scientist Mary, that conscious experiences have non-physical properties, called qualia. Mary has complete scientific knowledge of colours and colour vision without having had any colour experience. The central intuition in the KA is that, by seeing colours, Mary will learn what it is like to have colour experiences. Therefore, her scientific knowledge is incomplete, and conscious experiences have qualia. In this paper I consider an objection to the KA raised by Daniel Dennett. He maintains that the KA is vitiated by Jackson’s account of Mary’s scientific knowledge. While endorsing this criticism, I will defend the plausibility and relevance of the type of strategy involved in the KA by offering an account of Mary’s scientific knowledge. This account involves formulating a reasonable and not immediately false version of the physicalist thesis with regard to colour experiences. Whether this version of the KA is successful against this type of physicalism is not investigated here