3.342 In our notions there is indeed something arbitrary, but this is not arbitrary: if we have determined something arbitrarily then something else must be the case. (This stems from the essence of the notation.) 3.3421 A particular way of symbolizing may be unimportant, but it is always important that this is a possible way of symbolizing. And it is like this in philosophy generally: the particular proves unimportant time and again, but the possibility of each particular gives us an insight into the essence of the world. 3.343 Definitions are rules for translation from one language into another. Every right sign-language must allow of translation into every other by means of such rules: This is what they must all have in common. 3.344 That which signifies in a symbol is the common feature of all symbols that can take its place following the rules of logical syntax. W is claiming more here than that all languages must be representational or intentional; he is saying that, e.g., names in one language must correspond with names in another. Further, I think he's saying that, e.g., signs for items in "color space" or "music space" in any language must themselves somehow share in those spaces to do their work (he talks about gramophone grooves, musical scores, and acoustic sounds all sharing the same form). If the various linguistic signs don't share in the appropriate range of possibilities and impossibilities, their syntax (or grammar) will not allow them to perform all the functions necessary to the linguistic roles they're to play and they won't properly translate any signs that DO perform such functions. Walto