Mentalese

The concept of a proposition as something that can be expressed by sentences in both Mentalese and, say, English is an analogical extension of the concept of a proposition as something that can be expressed by sentences in both English and German.

Translationists are said to treat the coding of thoughts in ‘Mentalese’, whose structure is already known, into a natural language, just like translating a natural language, say Russian, in terms of another known language, say English (G 282). Incorporationists point out the circularity of (36b) because Mentalese, supposed to be intrinsically intelligible, is just English or some other variety of a natural language, and the translation maneuver only postpones the problem, [...]

But where does mentalese come from? If it is learned, then what is it related to in the preceding mentaleses? To avoid endless regress, [Jerry] Fodor postulates an internal language that is innate, a claim that he himself calls "horrendous" and "scandalous," yet inescapable.

[A]re natural languages merely vehicles for the communication of mentalese? Or does language itself play a role in the formation of our thought? The question is called critical, since a positive response to the latter (language does play a role) would call into question the assumption that all meaning is reducible to mentalese.

One suggestion is that there is a de facto correlation between words or sentences of natural language and expressions of mentalese and between the logical relations among the former and the causal relations among the latter. This is a curious idea. The alleged correlation is not empirically grounded.

[I]t is probably misleading to talk about the language of thought, or to talk about ‘Mentalese’, as if it were a single representational system. We should more properly, in the context of a thesis of massive mental modularity, talk about languages of thought, or Mentaleses.

[Jerry] Fodor's position stems from his theory, first articulated in The Language of Thought, that there is a type of internal system of representation contained within the human mind out of which thoughts are formed, similarly to the way sentences are formed out of individual words, a "language" which he refers to as "mentalese." Our concepts are the units out of which mentalese constructs thoughts. [...] Importantly, mentalese must be sufficiently rich to enable us to utilize it to learn the natural language of our birth, and we must have this type of system of representation prior to any development of natural language.