Where Lessing’s whole premise falls apart is when she suggests that the specialization of knowledge is a bad thing. Polymaths are very rare, especially today, unless you want a jack-of-all-trades. A gifted engineer is probably more educated in a number of fields than she is, most of which have a much higher barrier to entry than literature.

I do take this point, but what I wonder is what the relative percentages of each population are. My guess is that few people spent much time reading dickens and crafting letters. The difference does matter.

In other words, arguments are not self-contained in posts the way they are in larger expository writing. Arguments in blogs are evolutionary, iterative, and in some sense collaborative, since you get reader feedback at every step of the way. It’s true that blog writers don’t have to construct long chains of reasoning all at once — a form of mental discipline that is rapidly fading from the world — but they can and do construct robust, interesting arguments in a kind of pointillist fashion, with a supporting bit of evidence here, an alternative argumentative gambit there, etc.

I also agree that the pressure of timeliness can be destructive to thoughtfulness, but on the flip side it can also force continual rethinking of persistent themes and arguments. It can keep writing, and the mind of the writer, fresh and agile.

Certainly Lessing has a point, as do you. This new kind of writing is losing some of the virtues of the old kind. But it also has its own virtues, which I think will turn out to be much more rich and complex than your dismissal of “500-word posts” would have it.