No, hang on, don’t turn to Dear Mary yet. This is not as dull as it sounds. It’s just that I was mystified by not having heard of the term mechanistic insight when, to my husband, it was a common as an August blackberry on a Sussex hedgerow. ‘Look,’ he said, shaking some printouts from medical journals. ‘Mechanistic insights are two a penny.’

At first I thought it was simply a silly scientistic way of saying ‘How it works’. For example, one paper had the title: ‘Mechanistic insight into how multidrug resistant Acinetobacter baumannii response regulator AdeR recognises an intercistronic region.’ There is no need to know what any of this is about (except Acinetobacter baumannii is a bacterium that does nasty things in hospitals). But one might understand the title none the worse for the loss of its first three words, ‘Mechanistic insight into’.

This undoubtedly voguish term is both modest and suggestive of an all-encompassing theory. It will say how something works, but only from the perspective of its mechanical function: how the moving parts fit. Yet mechanistic implies a theory which, in its most thoroughgoing form, claims that analysing a system says all that can be known about it. Take apart a car, and that’s it.

People like the American linguist Leonard Bloomfield (who died in 1949) thought you could do that to language. ‘The materialistic (or, better, mechanistic) theory,’ he wrote in his book Language (1933), ‘supposes that the variability of human conduct, including speech, is due only to the fact that the human body is a very complex system.’ Never mind that language is spoken by people. Bloomfield was the kind of structuralist who saw the whole thing working very nicely on its own, only touched by human beings behaving as external stimuli dictated, as birds wake early for the dawn worm. Forget meaning: that is not susceptible to mechanistic insight.

For all their efforts to be objective, scientific papers wallow in metaphor. AdeR in that title doesn’t really ‘recognise’ anything, any more than a bimetallic thermostat recognises it’s too hot in the kitchen. There’s more to life’s Midsummer Night’s Dream than the rude mechanicals fathom by their crafts.