Metaphorical thinking, in the words of psychiatrist and philosopher Iain McGilchrist, “is the only way in which understanding can reach outside the system of signs to life itself. It is what links language to life.”

The word metaphor implies something that carries you over a gap (“meta” meaning “after/beyond” and “phore” meaning “bearer of” ), and is foundational in our understanding of the world. Metaphors matter because they tell us how we understand something, while also determining the way that we attend to it.

The metaphors we use are, of course, a product of our understanding. We see a similarity here or there, and find a felicitous comparison to aid or explain our understanding. But metaphors also determine the way we relate to things; our understanding is in no small way shaped by the metaphors we use. If, for example, we see the body as a machine, we will expect to see mechanistic relationships between its parts (as was the fashion in the 18th century).

Our attention is drawn towards aspects that confirm the metaphors we use, while shielding us from those that jar. To quote McGilchrist once again - and others, including Mark Twain, to whom similar quotes are attributed - “To the man with a hammer, everything begins to look like a nail.”

‘The kindling of a flame’

Educators could do worse than be shaped by the adage, often attributed to Socrates, that “Education is not the filling of a vessel, but the kindling of a flame.” As a metaphor, it contains some wise and prescient insights. It warns us that the primary job of teachers is not to fill brains with knowledge that someone, somewhere deems important. Rather, human beings have a native curiosity, something instinctive that students often unlearn through school. It is the job of the teacher to give oxygen to that curiosity and instil an inquisitive disposition. (Alistair McConville argued for this position in his Tes article, “In defence of the curious”, 16 March.)

Kindling a flame is a metaphor that stands in subversive defiance to a culture in which schools are often regarded as exam factories, and their success measured accordingly. In contrast to much that is valued by our culture, the work of developing curiosity in students is not measurable - it will not feature on league tables, nor elicit mention in inspection reports. But I would contend that it is the most valuable - and undervalued - work of any teacher.

If we are reaching for metaphors to describe teaching, we would do well to remember that whatever image we land on (programming computers/pottery/herding cats), it will not merely be descriptive of the job - it will determine how we relate to it.

Kenneth Primrose is head of religion and philosophy at Robert Gordon’s College in Aberdeen