L'intenzionalità della percezione: Chisholm e le scienze cognitive

The problem of intentionality is in essence a problem of the connection between human consciousness, inferior and superior psychic activities and the surrounding environment. The cognitive sciences seek to gather the constant behavioral and structural factors involved in these relations of meaning, by studying, in particular, neurophysiology and constructing explanatory models intended to give an account of the cognitive processes. The other level upon which the cognitive sciences operate is that of finding algorithms and computational instruments apt to reproduce, on an artificial basis, similar cognitive processes. This is more appropriately the task of artificial intelligence. Nevertheless, a fundamental impasse is constituted by the fact that the reproduction of a natural intentional system like that of man is impossible. Such a system, in fact, is not only able to establish a relationship of meaning with the world, but also able to be conscious, to believe that its own states are related to other things. Man can therefore provide a justification not only of his perceptive content, but also of the nature of his act. For Chisholm, hearing or seeing are properties, and as such they are always concerned with a unique transcendental subject, without having to take recourse to a middle term or to a set of properties shared by other subjects in order{o be justified. When one considers the doctrine of direct attribution in its principle aspects, one must ask himself what place remains for the object, not insofar as objectivized subject, but precisely as a reality external to our senses. The response given by Chisholm avoids the possibility of leading epistemic justification back to an experience of direct consciousness of the object and of its qualities. It seems inappropriate to ask oneself how it should be possible to justify evidence for that which exists outside of the subject.