Letters

Letters, for example, are an interesting transitional phenomenon,: a kind of written conversation that, as it were, stretches out the movement of talking at cross purposes before seeing each other's point. The art of writing letters consists in not letting what one says become a treatise on the subject, but making it acceptable to the correspondent. but it also consists, on the other hand, in preserving and fulfilling the measure of finality possessed by everything state in writing. The time lapse between sending a letter and receiving an answer is not just an external factor, but gives to this form of communication its proper nature as a particular form of writing. So we note that the speeding-up of the post has not led to a heightening of this form of communication but, on the contrary, to a decline in the art of letter-writing.

   Hans-Georg Gadamer, Truth and Method, Second Part, II, 3(i) "The model of the Platonic dialectic"

Is that so? The speeding up of the post took place in part through the development of railroads, which made it possible for visits to replace some letters. Then of course by the early 20th Century there was the telephone, which enabled one to talk at cross purposes in real time.