Internalism and externalism are two opposite ways of integration of explaining various subjects in several areas of philosophy.
These include human motivation, knowledge, justification, meaning, and truth.
Internalism is the thesis that no fact about the world can provide reasons for action independently of desires and beliefs.
An internal reason is, roughly, something that one has in light of one's own "subjective motivational set"—one's own commitments, desires (or wants), goals, etc.
However, Sasha doesn't desire to follow the moral law, and there is currently a poor person next to him.
Is it intelligible to say that Sasha has a reason to follow the moral law right now (to not steal from the poor person next to him), even though he doesn't care to do so?
The reasons internalist claims the following: the moral facts are a reason for Sasha's action not to steal from the poor person next to him only if he currently wants to follow the moral law (or if not stealing from the poor person is a way to satisfy his other current goals—that is, part of what Williams calls his "subjective motivational set").
Ontological internalism is the view that justification for a belief is established by one's mental states.
The new evil demon problem indirectly supports internalism by challenging externalist views of justification, particularly reliabilism.
Since this result is supposed to clash with our intuitions that the subject is justified in their beliefs in spite of being systematically deceived, some take the new evil demon problem as a reason for rejecting externalist views of justification.
According to the externalist, a believer need not have any internal access or cognitive grasp of any reasons or facts which make their belief justified.
[10]” Goldman notes that a reliable belief-forming process is one which generally produces true beliefs.
[10] In responding to skepticism, Hilary Putnam (1982[11]) claims that semantic externalism yields "an argument we can give that shows we are not brains in a vat (BIV).
The fact that the substance out in the world we were calling "water" actually had that composition at least partially determined the meaning of the word.
My utterance of "I am not a BIV" is true.To clarify how this argument is supposed to work: Imagine that there is brain in a vat, and a whole world is being simulated for it.
Apart from disputes over the success of the argument or the plausibility of the specific type of semantic externalism required for it to work, there is question as to what is gained by defeating the skeptical worry with this strategy.
Semantic externalism comes in two varieties, depending on whether meaning is construed cognitively or linguistically.
On a linguistic construal, externalism is the thesis that the meaning of a word is environmentally determined.
Externalism and internalism in semantics is closely tied to the distinction in philosophy of mind concerning mental content, since the contents of one's thoughts (specifically, intentional mental states) are usually taken to be semantic objects that are truth-evaluable.
The traditional discussion on externalism was centered around the semantic aspect of mental content.
Externalism is now a broad collection of philosophical views considering all aspects of mental content and activity.
The content externalist often appeal to observations found as early as Hilary Putnam's seminal essay, "The Meaning of 'Meaning'," (1975).
Critics of the view have questioned the original thought experiments saying that the lessons that Putnam and later writers such as Tyler Burge (1979,[17] 1982[18]) have urged us to draw can be resisted.
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.