There is substantial controversy, however, as to exactly what the larger segment of language in question consists of.
In recent years, the debate surrounding semantic holism, which is one among the many forms of holism that are debated and discussed in contemporary philosophy, has tended to centre on the view that the "whole" in question consists of an entire language.
[1] In the 1950s, the agreement that seemed to have been reached regarding the primacy of sentences in semantic questions began to unravel with the collapse of the movement of logical positivism and the powerful influence exercised by the later Ludwig Wittgenstein.
If, in addition, no limits are placed on the size of K (as in the cases of Davidson, Quine and, perhaps, Wittgenstein), then K coincides with the "whole" of L. The many and substantial problems with this position have been described by Michael Dummett, Jerry Fodor, Ernest Lepore and others.
In the first place, it is impossible to understand how a speaker of L can acquire knowledge of (learn) the meaning of E, for any expression E of the language.
Semantic holism, in this sense, also fails to explain how two speakers can mean the same thing when using the same linguistic expression, and therefore how communication is even possible between them.
Given a sentence P, since Fred and Mary have each mastered different parts of the English language and P is related to the sentences in each part differently, the result is that P means one thing for Fred and something else for Mary.
Since there is a very tight relationship between the content of a mental state M and the sentence P, which expresses it and makes it publicly communicable, the tendency in recent discussion is to consider the term "content" to apply indifferently both to linguistic expressions and to mental states, regardless of the extremely controversial question of which category (the mental or the linguistic) has priority over the other and which, instead, possesses only a derived meaning.
By making it impossible to explain language learning and to provide a unique and consistent description of the meanings of linguistic expressions, it blocks off any possibility of formulating a theory of meaning; and, by making it impossible to individuate the exact contents of any propositional attitude—given the necessity of considering a potentially infinite and continuously evolving set of mental states—it blocks off the possibility of formulating a theory of the mind.
The key to answering this question lies in going back to Quine and his attack on logical positivism.
The logical positivists, who dominated the philosophical scene for almost the entire first half of the twentieth century, maintained that genuine knowledge consisted in all and only such knowledge as was capable of manifesting a strict relationship with empirical experience.
Quine's holistic argument against the neo-positivists set out to demolish the assumption that every sentence of a language is bound univocally to its own set of potential verifiers and falsifiers and the result was that the epistemological value of every sentence must depend on the entire language.
As Quine states it: All of our so-called knowledge or convictions, from questions of geography and history to the most profound laws of atomic physics or even mathematics and logic, are an edifice made by man that touches experience only at the margins.
Numerous philosophers of language have taken the latter avenue, abandoning the early Quinean holism in favour of what Michael Dummett has labelled semantic molecularism.
Peter Pagin, in an essay called Are Compositionality and Holism Compatible identifies three points of incompatibility between these two hypotheses.
The second incoherence consists in the fact that a necessity to attribute "strange" meanings to the components of larger expressions would apparently result from any attempt to reconcile compositionality and holism.
According to Fodor and Lepore, holistic inferential role semantics leads to the absurd conclusion that part of the meaning of "brown cow" is constituted by the inference "Brown cow implies dangerous."
In fact, with this many to one relation from Global Roles to meanings, it is possible to change opinions with respect to an inference consistently.
But if there is no one to one assignment, then B's change in belief in the inference about brown cows does not necessarily imply a difference in the meanings of the terms he uses.
Since the concept of semantic holism, as explained above, is often used to refer to not just theories of meaning in natural languages but also to theories of mental content such as the hypothesis of a language of thought, the question often arises as to how to reconcile the idea of semantic holism (in the sense of the meanings of expressions in mental languages) with the phenomenon called externalism in philosophy of mind.
Externalism is the thesis that the propositional attitudes of an individual are determined, at least in part, by her relations with her environment (both social and natural).
In it, he described his famous thought experiment involving Twin Earths: two individuals, Calvin and Carvin, live, respectively, on the real earth (E) of our everyday experience and on an exact copy (E') with the only difference being that on E "water" stands for the substance
But in the case of Goodfrey the belief is correct because in the counterfactual society in which he lives "arthritis" is defined as a disease that can include the thighs.
Frederik Stjernfelt identifies at least three possible ways to reconcile them and then points out some objections.
The first approach is to insist that there is no conflict because holists do not mean the phrase "determine beliefs" in the sense of individuation but rather of attribution.
But if one is a "realist" about mental states, then why not say that we can actually individuate them and therefore that instrumentalist attributions are just a short-term strategy?
The problem here is that the whole scheme is based on the idea that certain relations are constitutive (i.e. necessary) for the determination of the beliefs and others are not.
But this implies the abandonment of a central pillar of holism: the idea that there can be no one to one correspondence between behavior and beliefs.
There will be cases in which the beliefs that are determined externally correspond one to one with perceptual states of the subject.
These are some of the problems and questions that have still to be resolved by those who would adopt a position of "holistic externalism" or "externalist holism".