Internalism and Externalism - Philosophy of Mind

Philosophy of Mind

Within the context of the philosophy of mind, externalism is the theory that the contents of at least some of one's mental states are dependent in part on their relationship to the external world or one's environment.

The traditional discussion on externalism was centered around the semantic aspect of mental content. This is by no means the only meaning of externalism now. Externalism is now a broad collection of philosophical views considering all aspects of mental content and activity. There are various form of externalism that consider either the content or the vehicles of the mind or both. Furthermore, externalism could be limited to cognition, or it could address broader issues of consciousness.

As to the traditional discussion on semantic externalism (often dubbed content externalism), some mental states, such as believing that water is wet, and fearing that the Queen has been insulted, have contents we can capture using 'that' clauses. The content externalist often appeal to observations found as early as Hilary Putnam's seminal essay, "The Meaning of 'Meaning'," (1975). Putnam stated that we can easily imagine pairs of individuals that are microphysical duplicates embedded in different surroundings who use the same words but mean different things when using them.

For example, suppose that Ike and Tina's mothers are identical twins and that Ike and Tina are raised in isolation from one another in indistinguishable environments. When Ike says, "I want my mommy," he expresses a want satisfied only if he is brought to his mommy. If we brought Tina's mommy, Ike might not notice the difference, but he doesn't get what he wants. It seems that what he wants and what he says when he says, "I want my mommy," will be different from what Tina wants and what she says she wants when she says, "I want my mommy."

Externalists say that if we assume competent speakers know what they think, and say what they think, the difference in what these two speakers mean corresponds to a difference in the thoughts of the two speakers that is not (necessarily) reflected by a difference in the internal make up of the speakers or thinkers. They urge us to move from externalism about meaning of the sort Putnam defended to externalism about contentful states of mind. The example pertains to singular terms, but has been extended to cover kind terms as well such as natural kinds (e.g., 'water') and for kinds of artifacts (e.g., 'espresso maker'). There is no general agreement amongst content externalists as to the scope of the thesis.

Philosophers now tend to distinguish between wide content (externalist mental content) and narrow content (anti-externalist mental content). Some, then, align themselves as endorsing one view of content exclusively, or both. For example, Jerry Fodor (1980) argues for narrow content (although he comes to reject that view in his 1995), while David Chalmers (2002) argues for a two dimensional semantics according to which the contents of mental states can have both wide and narrow content.

Critics of the view have questioned the original thought experiments saying that the lessons that Putnam and later writers such as Tyler Burge (1979, 1982) have urged us to draw can be resisted. Frank Jackson and John Searle, for example, have defended internalist accounts of thought content according to which the contents of our thoughts are fixed by descriptions that pick out the individuals and kinds that our thoughts intuitively pertain to the sorts of things that we take them to. In the Ike/Tina example, one might agree that Ike's thoughts pertain to Ike's mother and that Tina's thoughts pertain to Tina's but insist that this is because Ike thinks of that woman as his mother and we can capture this by saying that he thinks of her as 'the mother of the speaker'. This descriptive phrase will pick out one unique woman. Externalists claim this is implausible, as we would have to ascribe to Ike knowledge he wouldn't need to successfully think about or refer to his mother.

Critics have also claimed that content externalists are committed to epistemological absurdities. Suppose that a speaker can have the concept of water we do only if the speaker lives in a world that contains H₂O. It seems this speaker could know a priori that she thinks that water is wet. This is the thesis of privileged access. It also seems that she could know on the basis of simple thought experiments that she can only think that water is wet if she lives in a world that contains water. What would prevent her from putting these together and coming to know a priori that the world contains water? If we should say that no one could possibly know whether water exists a priori, it seems either we cannot know content externalism to be true on the basis of thought experiments or we cannot know what we are thinking without first looking into the world to see what it is like.

As mentioned, content externalism (limited to the semantic aspects) is only one among many other options offered by externalism by and large.

See also

• Externalism
• Twin Earth
• The extended mind