La naturalizzazione dell’intenzionalità Sandro Nannini (Università di Siena)

1. La naturalizzazione dell’intenzionalitàSandro Nannini (Università di Siena) Siena, LS09 - Intenzionalità

2. Il problema mente-corponella vita quotidiana EE……P(+M)(D)A SD SP..C…N R (Suonano, vado ad aprire!)  Siena, LS09 - Intenzionalità

3. Il dualismo interazionistico P …D  SD  SP..CPCD..N  R Difficoltà: la chiusura del mondo fisico Siena, LS09 - Intenzionalità

4. Il naturalismo SD  SP..CP..CD..N  R Teoria dell’identità Funzionalismo Eliminativismo Riduzionismo ontologico / Riduzionismo metodologico Siena, LS09 - Intenzionalità

5. Naturalising mental states • A mental State X is naturalised iff: • We know how X is implemented by a functional state Y that has the same causes and brings about the same effects than X (functional reduction). • We know how the functional state Y is implemented by a brain process Z (neurological implementation). “X” belongs to the language of folk psychology, “Y” to the language of cognitive psychology, “Z” to the language of neurosciences. Siena, LS09 - Intenzionalità

6. Naturalising mental states • Functional reduction [1] is a task of cognitive psychologists, neurological implementation [2] is a task of neuroscientists. • The step (2) presupposes the step (1) and vice versa (top down explanation and bottom up explanation). • Both steps presuppose a previous conceptual analysis and modification of the language of folk psychology (this is the task of philosophers). Siena, LS09 - Intenzionalità

7. Weak Naturalism and Strong Naturalism • W.N.: The truth of (1) is sufficient to naturalise X and such a naturalisation is in principle always possible. • S.N.: Also the truth of (2) is necessary to naturalise X. If no Y seems to completely implement X and be completely implemented by Z then either Y was not found out yet or there is a residue of X that cannot be naturalised. Such a residue does not belong to the reality. It is a “fiction” of our mind that has no causal efficacy. Siena, LS09 - Intenzionalità

8. Perception and sensory-motor coordination • Animals acquired the ability to perceive some features of the external world and of their own body in order to execute movements apt to increase the probability to survive (e.g. by catching preys or avoiding plunderers). Siena, LS09 - Intenzionalità

9. Perception and sensory-motor coordination • Human senses and human sensori-motor coordination are the result of biological evolution. Biological evolution Siena, LS09 - Intenzionalità

10. Perception and sensory-motor coordination:Representation-Action Theory (RAT) • Perceptions can be conscious or unconscious: in both cases they are mental representations of the internal and external world. • Human beings construct a representation of the external world in order to move and act in it. Siena, LS09 - Intenzionalità

11. The computational brain • According to the RAT the brain acquires by means of the senses a certain amount of information about some regularities of the external world as regards the distribution of matter and physical events in space and time and changes the format of such information step by step until a pattern of motor neurons activity able to trigger a right motor response is produced. Siena, LS09 - Intenzionalità

12. Styles of brain computation No!!! Symbolic representations A Brooks’ robot Unlikely! No representations May be! Subsymbolic representations

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15. Naturalising perceptions according to the RAT Functional reduction • A perception is functionally reducible to an intermediate step in the information processing of sensori-motor coordination • Therefore it is similar to the activity pattern of hidden units in an artificial neural network and is describable as a vector in a state space. Siena, LS09 - Intenzionalità

16. Naturalising perceptions according to the RAT Neural implementation • Perceptions as vectors in a space state are biologically implemented by the dynamics of brain processes. Siena, LS09 - Intenzionalità

17. Criticisms on the RAT • The sensory motor coordination does not need any inner representation of the external world (Antirepresentationalism; e.g. Brooks’ robots). • Perceptions are conscious. Brain processes cannot be conscious (Mind-Body Problem: can consciousness be naturalised?). • Perceptions are ‘intentional’ states. No brain process can be ‘intentional’ (semantic relations are not reducible to causal relations): • The possibility of deceptive perceptions • The neural implementation of contents • The identification of a real object by means of a phenomenal object. Siena, LS09 - Intenzionalità

18. Criticisms on the RAT • The sensory motor coordination does not need any inner representation of the external world (Antirepresentationalism; e.g. Brooks’ robots). Siena, LS09 - Intenzionalità

19. A reply to (1) Mice in a labyrinth Siena, LS09 - Intenzionalità

20. A reply to (1) • M1s recognise red (R), green (G) and yellow (Y) colours and follow these rules: • ‘If R go to right’ • ‘If G go to left’, • ‘If Y go ahead’ • Therefore they are able to reach the food if they enter the labyrinth from South. If they enter from West they have no chance to reach the food. Siena, LS09 - Intenzionalità

21. A reply to (1) M2s instead enter the labyrinth sometimes from South and sometimes from West. They can reach the food in both cases because they are able to remember from which entrance they came and to learn by trial and error that if they enter from South they must follow the rule (1) but if they enter from West they must follow the rule (1*), that is, ‘If R go ahead’. Siena, LS09 - Intenzionalità

22. A reply to (1) M3s are able to construct by trials and errors a map of the labyrinth. They remember that after entering the labyrinth from South they went to East as they turned to left at the red square. Moreover they somehow have learned (or have the inborn knowledge) that East and West are opposite directions. Therefore, even if they never used the entrance West they are able to forecast that if they entered the labyrinth from West they should go ahead at the red square instead of going to right as they always did till that moment in their life. Siena, LS09 - Intenzionalità

23. A reply to (1) In other words, the richer and more ‘objective’ the representation of the labyrinth is the more flexible and efficient the behaviour of the mouse is. Similarly human beings cannot work like Brooks’ robots. They need an inner representation of the environment in which they act. Otherwise their behaviour would not be so flexible as it is. Mental representations are in humans ‘multi-purpose’ representations. Siena, LS09 - Intenzionalità

24. Criticisms on the RAT • Perceptions are conscious. Brain processes cannot be conscious (Mind-Body Problem: can consciousness be naturalised?). Siena, LS09 - Intenzionalità

25. A reply to (2) There is a double disjunction between perception and consciousness: • Blindsight • Anton’s syndrome Siena, LS09 - Intenzionalità

26. Blindsight Perception without consciousness Blindsight allows people to use visual information they get through their eyes even though they have no consciousness of the visual experience. Siena, LS09 - Intenzionalità

27. Anton’s syndrome Consciousness without perception The doctor asks what is on the table in front of you: “A clock” you say as though the doctor is an idiot. Siena, LS09 - Intenzionalità

28. A reply to (2) • Conclusion: you can perceive something without been aware of perceiving it and you can be aware of perceiving something without really perceiving it. • Consciousness and perception are two distinct phenomana implemented by different brain processes. • The RAT naturalises only ‘mere perceptions’, that is, the functional basis common to all perceptions independently of their being conscious or unconscious. Siena, LS09 - Intenzionalità

29. Criticisms on the RAT • Perceptions are ‘intentional’ states. No brain process can be ‘intentional’ (semantic relations are not reducible to causal relations): • The possibility of deceptive perceptions Siena, LS09 - Intenzionalità

30. A reply to (3a) R F. Dretske’s theory: R(O*) is true iff OB is true. A girl sees a cat and her perception is true because it is caused by an animal that is really a cat. O* B B O S Siena, LS09 - Intenzionalità

31. An objection on Dretske‘s theory R The girl is looking at a squirrel but in the dark she sees a cat: O’ R(O*) is true but R(O*) is false. O* B B O‘ S Siena, LS09 - Intenzionalità

32. The RAT reply to (3a) The girlspursuesthe goal G to carry the catin her arms (D(G*)) and executes an action A in order to get G. Perceiving the cat (R(O*)) is necessary to get G because A is caused by D(G*) & R(O*): OR(O*) [& D(G*)]AG Siena, LS09 - Intenzionalità

33. A reply to (3a) D(G*) R(O*) B G A O T1 T2 Siena, LS09 - Intenzionalità

34. A reply to (3a) The RAT Dretske’s theory Mind R(W* S*) Mind R(W*) R(S*) R(O*) Emotions R(O*) D(G*) Body Body B B Hand etc. S S G Physical world O Physical world O Siena, LS09 - Intenzionalità

35. A reply to (3a) (a) is a valid objection against Dretske’s theory but not against the RAT. Siena, LS09 - Intenzionalità

36. Criticisms on the RAT • Perceptions are ‘intentional’ states. No brain process can be ‘intentional’ (semantic relations are not reducible to causal relations): • Semantic relations are necessary conceptual relations. Causal relations are contingent empirical relations: how can a chain of causal relations implement a semantic relation? Siena, LS09 - Intenzionalità

37. A reply to (3b) Contents can be naturalised by means of the ‘adverbial theory’ (of perceptions etc.). “I see red” means “I see redly”: the content of a mental representation is part of its form. Therefore it can be implemented by certain physical properties of a brain process. Siena, LS09 - Intenzionalità

38. An objection to the adverbial theory 1 1 I see a green square I see a red circle Distinguishing between (1) and (2) is impossible. I see greenly, squarely, redly, and circulary I see a green circle I see a red square 2 2 Siena, LS09 - Intenzionalità

39. A reply to 3b(In defence of adverbial theory) • Many neuroscientists think that the form and the colour of a same object are connected by the brain thanks to a common temporal code (synchronisation). • Therefore the difference between perceiving (1) and perceiving (2) might be implemented by the difference between two dynamics of the brain. Siena, LS09 - Intenzionalità

40. Criticisms on the RAT • Perceptions are ‘intentional’ states. No brain process can be ‘intentional’ (semantic relations are not reducible to causal relations): • A functional state of the brain cannot identify the real object from which is caused and on which the action of the agent is directed. Therefore the RAT is insufficient to explain why perceptions are instead sufficient to identify external objects. Siena, LS09 - Intenzionalità

41. A reply to 3c: the 1-eaters and the 2-eaters 1000200000010000000200100000000001222200000010000000200100000000001222?????????????????????????????? 100020000001000 000020010000000 000122220000001 000000020010000 0000001222????? ??????????????? ?????????? 1000200000 0100000002 0010000000 0001222200 0000100000 0020010000 0000001222 ?????????? ?????????? ?????????? Which is the right representation? It depends on what you eat! Siena, LS09 - Intenzionalità

42. A reply to (3c): frogs and flies • A frog recognizes flies as food only if they are moving. • We human beings instead recognize flies as flies independently of their movements. • Therefore, the representation that an animal has of its environment is functional to the actions that it is able to execute in that environment. Siena, LS09 - Intenzionalità

43. A reply to (3c): frogs and flies • It is not the case that we human beings see flies as they are, frogs instead see them as they appear to them. Siena, LS09 - Intenzionalità

44. A reply to (3c) • Mental representations are constructions of the mind (=brain), not the copies of real objects. • There is similarity between the activity patterns of hidden units in an artificial neural network and mental representations: they are a representation (= a state space partition) of the input apt to get the desired output. • Every species lives in its own phenomenal world adapted to a certain kind of interaction with the real physical world. Siena, LS09 - Intenzionalità

45. Conclusion • Perceptions can be naturalised only if the common sense concept of ‘perception’ is radically changed: perceptions are not copies of real objects passively received from the external world but formats given to sensory inputs in order to construct a stable and multi-purpose model of reality that is able to control the very flexible behaviour of human beings. • These perceptions can be functionally reduced and therefore can be implemented by brain processes. Siena, LS09 - Intenzionalità

46. Action theory and cognitive turn by Sandro Nannini (University of Siena) Siena, LS09 - Intenzionalità

47. Linguistic turn and cognitive turn • From the meaning of psychological terms to empirical hypotheses on the nature of mental states (from G. Ryle to naturalism in the philosophy of mind). • My aim is to defend the causal theory of action from a naturalistic point of view by doing a “cognitive turn” in action theory as well. Siena, LS09 - Intenzionalità

48. “Intentionalists” and “causalists”Intentional explanations • “She raised her arm because she intended to greet a friend”. • “She did X because she intended to get Y”. • “A did X because A intended to get Y and believed that doing X had brought about her getting Y”. • IA(Y)  BA(XY)  X Siena, LS09 - Intenzionalità

49. “Intentionalists” and “causalists”Intentional descriptions • “She raised her arm because she intended to raise it” • “She did X because she intended to do X”. • “Her doing X was intentional”. • IA(X)  X • Every intentional explanation implies an intentional description; “IA(Y)  BA(X Y)X” can be so expanded: • 1) IA(Y)  BA(X Y) IA(X) • 2) IA(X) X Siena, LS09 - Intenzionalità

50. “Intentionalists” and “causalists”“The logical connection argument” • L. Wittgenstein, G. Anscombe, A. Melden, and G.H. von Wright: the causal theory of action is false because it is logically impossible that an intention is the cause of an action. • 1) The direct “Logical connection argument”: In “IA(X)X” the relation “” cannot be causal because IA(X) mentionsX. • 2) The “verification argument” (von Wright): the presence of IA(X) can be verified only by means of the presence of X. Siena, LS09 - Intenzionalità