Sime, you're wrong about the arrow example, and about a "look up table." Let's see if I can make this clear. Wittgenstein asks in (PI 454), "How does it come about that this arrow -----------> points?" Any sign, be it a word or an arrow, only has an application, a use, that we together as a people, i.e., in socially given situations, give to it. "This pointing is not a hocus pocus which can be performed only by the soul [the soul, as used here, should be understood as the inner thing, the subjective]. So, it seems to me, and not only me, but many other interpreters, that Wittgenstein is saying the exact opposite of your point. This is clear throughout the PI, starting at the beginning when he talks about language-games. — Sam26
" This pointing is not a hocus pocus which can be performed only by the soul "
Does not support your thesis or yield the conclusion
"Any sign, be it a word or an arrow, only has an application, a use, that we together as a people, i.e., in socially given situations, give to it."
unless by that you mean
"Any sign, be it a word or an arrow, only has an application, a use, that
a person gives to it."
Which is logically coherent, and avoids the unintelligible requirement of social consensus with respect to meaning and truth, that you often appear to imply.
Notice the context of the PI 454, in which he barely mentions social consensus. He is merely remarking on the distinction between what is said or thought
a priori in relation to a sign (e.g the sign's stipulated definition) in comparison to it's actual
a posteriori application. The difference between the definition of a sign and it's eventual application - that is under-determined by the definition, undermines the possibility of any theory of semantics, whether private or public.
"Infinity" is a striking example of a word whose use necessarily belies any stipulated definition. Our convention defines "infinity" as meaning boundless, endless, or larger than any number..., and yet any particular use of the sign of "infinity", such as in an executed computer program, eventually halts and involves strictly finite reasoning and demonstration, - in apparent contradiction to it's stated definition as being "endless" - until that is, it is remembered that the actual uses of the phrases "boundless energy" , "infinite love" and what have you, are also finitistic...
In other words, "infinity" and "going on forever" can be considered as synonymous, but no two applications of either are the same, for they halt at different times or finite numbers, if at all.. Hence the synonymous definition of infinity is a misleading tautology that says nothing of implicative relevance and isn't the semantic ground of anything. This is the logical content of the so-called "private" language argument, and as demonstrated, applies equally to the shared definitions offered by public languages.
The "private language argument" isn't "no private meaning, therefore only public meaning", but rather "no private
theory of meaning, therefore no public theory of meaning either".
The concept of "potential infinity" partially circumvents the above issue by defining "infinity" to be an indexical referring to a fallible promise of a future finite number (as is done in computing), but fallible promises, by definition, lie outside of what is determinable by convention,implying the meaninglessness of a theory of so-called "infinite numbers" except as an empty syntactical construct.
Wittgenstein undoubtedly noticed that what is true regarding the definition of "infinity" is also true of every sign in every language, complementing Quine's attack on the analytic-synthetic distinction. For example, we say "Bachelor" is a synonym for "Unmarried Man", but no two individuals use the expressions synonymously. Synonymy isn't use - except when writing definitions.
And since the sentences of our language are infinite, we cannot even ground the linguistic notion of synonymy in personal or social conventions without appealing to a notion of logical implication, which leads to vicious regress if we think of logical implication as being reducible to convention. This observation of Quine in his attack on "truth by convention" predates the post-humus publication of PI by nearly two decades, and Wittgenstein was likely influenced by it. It rules out every stripe of meaning-theory so that neither phenomenalism, physicalism nor communitarianism can serve as semantic or epistemological "givens".