“Just because a result is absurd does not mean that the argument is a reductio ad absurdum. There are things that are inherently absurd, and so cannot be reduced to absurdity.”
So say Bernhardt and Stemberger (1998: 24) on the rule-based analysis of phonological acquisition, having presented some rather silly cases as being “entirely parallel” to such linguistic analyses in non-linguistic domains.
For example, in the rule-based approach, children are said to have a process of Final Devoicing at some early stage of acquisition, which has to be suppressed as acquisition proceeds in order for their productions to match target adult productions.
Bernhardt and Stemberger say this is like proposing a process of “squiggleization” in which children replace details of pictures with squiggles, until this process comes to be suppressed at a later stage of development.
Anticipating the criticism that this is an unfair parody and reductio ad absurdum, they insert footnote 7, as above.
It’s a fair point – the rule-based model is clearly inadequate – until you start to wonder whether the aggressiveness of this critique of rule-based approaches (and its disdain) may not be something of a figleaf in advance of the only slightly less shaky constraint-based model they go on to espouse. For which many silly analogies could be provided, but that’s a story for another day.
Bernhardt & Stemberger (1998), Handbook of Phonological Development. London: Academic Press