Ideal, formal, and natural languages
Hand or hammer. An ideal language is an artificial, constructed language. (Historically this is not quite correct. Cf., ideas about Hebrew being the language spoken in Paradise. Cf., also, Heidegger on philosophical languages.) An artificial language is an instrument like a hammer. Constructed by us, and used by us by means of our natural ‘instruments’. And an artificial language can be used only by means of a natural language (this includes its construction), the same way a hammer can only be used by someone who has hands. This holds also for artificial languages that in some sense (precision, clarity, scope) surpass the natural languages by means of which they are constructed. (Cf., Frege on the telescope and the eye.) In some settings this dependence may not be so obvious: mathematics, programming languages, machine code. But think about what we mean when we say that a machine calculates, thinks, … In the end it comes down to interpretation, or translation, into our vernacular. That seems implausible only as long as we forget that our experience (action) is much broader than that which is covered by means of our natural language. (Cf., note dd. 14/07/98: “The role of experience. Experience is not what is expressed in language, at least not solely, but what makes language possible in the first place. It is therefore both transcendent and transcendental. This holds not just for empirical statements and empirical concepts, but across the board. Cf., Wittgenstein on the relation between mathematics and experience. “)
Hence, it seems plausible to consider a natural language to be like a hand, and not like a hammer. However, although we call a natural language ‘natural’ it is not something we were born with: it has to be acquired. This leads straightforward to the assumption of a language of thought. It is the LoT that is the true natural language. (Cf., the biological metaphors in Chomsky’s work, for example: ‘language organ’.)
But then the problem arises as to how this LoT has meaning (and hence conveys meaning to the acquired language. Question: on such a picture would an artificial language need the mediation of a natural language? Or could it be considered to be tied directly to the LoT, in the same way as a natural language?), i.e., how the LoT relates to the world. Explaining that in terms of a natural language (and its relation to the world) obviously leads us straight into a vicious circle. To sharpen the issue, consider theories of direct (rigid) designation. Given some assumptions about the inherent (i.e., non-reducible) indexicality of natural languages, such theories seem at least partly right. From thereon we can turn straight to the steamship metaphor of Putnam: neither natural languages nor a LoT is a natural instrument in the sense of a hand.
Interesting question: could we discover an ideal language? I.e., could we come up against some code that turns out to be (more) ideal? Not clear what that means. Notice that we would need to be able to interpret such a code in our own language, in order for it to be recognisable as a language in the first place.