I don’t know that much about urban development yet, but it fascinates me, and I do know something about language. The problem is that the something that I know suggests that this may be a poor analogy.
Hence DFW’s conclusion. We can’t assume those planning our cities are credible just because they’re making the plans. But we need rules and guidance—an entirely hands-off approach will create interesting cities with multitudes of serious problems.
Here he’s analogizing between urban planners and prescriptive linguists. But David Foster Wallace’s essay (and further works), wherein he arrives at the conclusion that prescriptivism is needed, has been taken apart by better linguists and bloggers than I, Language Log and Language Hat. Language Log has a whole category called Prescriptivist Poppycock.
This all suggests a rather different analogy between urban planners and prescriptivists, namely that they are talking nonsense well over half the time and for the most part we’d be better off without them, because the object of their concern is perfectly capable of developing organically and effectively, entirely on its own, in ways that serve its function.
For what it’s worth, that doesn’t strike me as particularly valid either. But since it’s an equally good, or maybe better, description of the relationship of prescriptivists to language, I’d recommend that urbanists be careful taking prescriptivists as their model!
Nevertheless, I think Drew makes a valid point in the final paragraph:
Maybe this is why urbanists keep returning to Jane Jacobs. She reconciles these approaches in The Death and Life of Great American Cities by merging a Descriptivist’s eye for the way cities actually are (not how they should be) with a Prescriptivist’s desire to make cities better—by nurturing what’s already good in those cities rather than trying to recreate them.
In agreeing with the final idea, I might resurrect the analogy at a more sophisticated level: both urban planners and prescriptivists ostensibly want to make things better, and both can easily end up doing nothing of the sort, because the systems they are trying to manipulate are organic and complex and don’t necessarily respond the way you expect to manipulation.