The fundamental problem of communication is that the Sender can add to the circumstance of the Receiver, but it can never create new circumstances. In simpler words, everything that is said can only be received as an appendage to another previous text that cannot be changed. This text is the previous life of the Receiver.
If we had for example two persons hypothetically devoid of any form of previously negotiated language in a given environment. Say one of them knows that if you step into a red square on the ground you receive a shock. When the second one comes close to the red square, the first one can shout, jump, make noises, pretend to receive a shock, he can do all sorts of things, but all of them will only be understood according to what the second person has lived previously.
Now imagine the first person has shouted and screamed but nevertheless the second person did step on the red square. And also suppose there is a blue square and it also gives a shock. If, when the second person comes close to it the first makes the same screams and shouts, the second person will probably understand that he should not step on it.
But the previous experience (shouting+shock) does not isolate the communication act from the second person’s history. If the second person had had an occasion where upon stepping into an blue square he found food, he would be inclined to understand the first guy’s shouting differently.
Said like that, it seems like common sense. But most communication acts do presuppose a vast amount of isolation. We presuppose that our utterances do have a meaning of their own. We assume to be able to ignore the circumstance in order to communicate exactly. But to understand is always an act of interpretation of a circumstance.
Negotiation of language is in itself a form of isolating previous circumstances. Everyone living today has been subjected to an amount of language negotiation so intense that it is easy to see communication acts as pure and self-evident. In fact when dealing with day-to-day events the common language can solve most issues clearly. But this doesn’t mean the language has been isolated from previous circumstance, but merely that the circumstance itself has been rehearsed so much it becomes not an issue of communication but merely of synchronization.
In some ways, the fundamental problem of communication indicates that communication itself is impossible, that there can be at most good approximations. But i prefer saying that communication is possible, it is only unperfectible: communication cannot be a perfect transmission unless you have total control over the Receiver (which is only possible in mechanical communication experiments).