Andy Clark & David J. Chalmers, The Extended Mind, ANALYSIS 58: 1: 1998 p.7-19

Questione fondamentale: Where does the mind stop and the rest of the world begin?

Primo caso di studio:

Un agente umano (nel futuro) che gioca a TETRIS per stabilire se un pezzo si inserisce o meno in uno slot, può:

a) ruotare mentalmente l’oggetto;

b) servirsi di un tasto che fa ruotare l’oggetto sullo schermo del computer;

c) servirsi di un impianto neurale che realizza la stessa rotazione del caso b) ma è attivato dal pensiero e visualizzato sulla propria retina.

I tre casi sono simili: a) e c) sono chiaramente interni, b) é esterno e distribuito tra soggetto e computer, ma:

If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing as part of the cognitive process, then that part of the world is (so we claim) part of the cognitive process. Cognitive processes ain't (all) in the head!

Cioè quello che in Andy Clark, “Memento's Revenge: Objections and Replies to the Extended Mind" to appear in R. Menary (ed) Papers On The Extended Mind viene chiamato: Parity Principle.

Per arrivare a ciò si usa la distinzione:

epistemic action <---> pragmatic action

Epistemic actions alter the world so as to aid and augment cognitive processes such as recognition and search.

Pragmatic actions, by contrast, alter the world because some physical change is desirable for its own sake.

Kirsh, D. & Maglio, P.. On distinguishing epistemic from pragmatic action. Cognitive Science 18:513-49. 1994

Quindi:

In these cases, the human organism is linked with an external entity in a two-way interaction, creating a coupled system that can be seen as a cognitive system in its own right. All the components in the system play an active causal role, and they jointly govern behavior in the same sort of way that cognition usually does. If we remove the external component the system's behavioral competence will drop, just as it would if we removed part of its brain. Our thesis is that this sort of coupled process counts equally well as a cognitive process, whether or not it is wholly in the head.

C&C chiamano la loro posizione Active Externalism.

This externalism differs greatly from standard variety advocated by Putnam (The meaning of `meaning' -1975) and Burge (Individualism and the mental.1979),

Nell’esempio di Putnam le caratteristiche esterne responsabili delle differenze di credenze (acqua = H₂O o acqua = XYZ – Terra/Terra Gemella) sono distanti, passive. This is reflected by the fact that the actions performed by me and my twin are physically indistinguishable, despite our external differences. In the cases we describe, by contrast, the relevant external features are active, playing a crucial role in the here-and-now.

Si potrebbe rifiutare questo tipo di esternalismo identificando il cognitivo con il conscio, dal momento che appare molto poco plausibile che la coscienza si estenda al di là dell’individuo. Ma l’identificazione tra coscienza e processo cognitivo è ingiustificata, poiché esistono molti processi che giocano un ruolo centrale nella mia cognizione ma non sono coscienti.

More interestingly, one might argue that what keeps real cognition processes in the head is the requirement that cognitive processes be portable… the trouble with coupled systems is that they are too easily decoupled. Ma questo è un fatto contingente. The real moral of the portability intuition is that for coupled systems to be relevant to the core of cognition, reliable coupling is required.

Language appears to be a central means by which cognitive processes are extended into the world.

So far we have spoken largely about "cognitive processing", and argued for its extension into the environment. Some might think that the conclusion has been bought too cheaply. Perhaps some processing takes place in the environment, but what of mind? Everything we have said so far is compatible with the view that truly mental states - experiences, beliefs, desires, emotions, and so on - are all determined by states of the brain. Perhaps what is truly mental is internal, after all?

We propose to take things a step further. While some mental states, such as experiences, may be determined internally, there are other cases in which external factors make a significant contribution. In particular, we will argue that beliefs can be constituted partly by features of the environment, when those features play the right sort of role in driving cognitive processes. If so, the mind extends into the world.

Secondo caso di studio:

(to address the portability issue and to extend the treatment to the more central case of an agent’s beliefs about the world.)

• Inga hears of an intriguing exhibition at MOMA. She thinks, recalls it's on 53rd St, and sets off.
• Otto suffers from a mild form of Alzheimer's, and as a result he always carries a thick notebook. When Otto learns useful new information, he always writes it in the notebook. He hears of the exhibition at MOMA, retrieves the address from his trusty notebook and sets off.

Just like Inga, Otto walked to 53rd St. because he wanted to go to the museum and believed that it was on 53rd St (even before consulting his notebook, a meno che non si considerino vere credenze solo quelle che si hanno sull’istante, ma allora anche Inga non credeva che il MOMA fosse nella 53 strada prima di recuperare questa informazione dalla sua memoria). Otto’s long-term beliefs just weren’t all in his head.

Per essere inclusi nel sistema cognitivo di un individuo le sue credenze devono essere:

1. costantemente disponibili e usate,

2. accessibili senza difficoltà,

3. immediatamente accettate (non sottoposte a scrutinio critico)

What about socially extended cognition?

Anche in questo caso non sembra che ci siano validi motivi di principio per escludere le credenze di un’altra persona (su cui faccio costante e certo affidamento) tra le mie credenze.

In questo caso il linguaggio gioca un ruolo centrale. Senza linguaggio saremmo chiusi in un solipsismo cartesiano in cui tutto il carico cognitivo ricade su processi interni. Con il linguaggio possiamo scaricarlo parzialmente nel mondo. Language, thus construed, is not a mirror of our inner states but a complement to them. It serves as a tool whose role is to extend cognition in ways that on-board devices cannot. Indeed, it may be that the intellectual explosion in recent evolutionary time is due as much to this linguistically-enabled extension of cognition as to any independent development in our inner cognitive resources.

Infine anche la concezione dell’io dovrebbe essere riconsiderata. Come il proprio sé supera i confini dei propri stati coscienti, così potrebbe superare anche i confini della pelle.