What is a metaphor?

Some advice on writing metaphors

I do love metaphors. I adore reading unexpected ones. I get a particularly acute, almost bodily sense of satisfaction when one occurs to me out of the blue. And because they mean so much to me, I get particularly irritated with metaphors that don’t illuminate the thing they are describing in a new way.

A metaphor is a comparison between two things, which might seem like an obvious thing to say, but you would be surprised at how often this is forgotten, even by published authors. To be more specific, a metaphor is a comparison between two things, where the properties of one object or idea are transferred onto another. We understand the thing being described in a new and often unexpected way because the properties of that one thing are suddenly, remarkably, carried over to the thing being described.

It’s easiest to explain this by reference to an example. This exquisite metaphor comes from Sally Rooney’s novel Normal People. In this sequence, the narrator is graduating from her university degree, and though she is happy, there is also a lingering sense of unreality about her situation. Rooney writes,

‘The sky was extremely blue that day, delirious, like flavoured ice.’

So, what is being compared here? The sky is being compared to flavoured ice. To get more specific about it, the properties of the flavoured ice, the colour and in particular the artificiality of the colour, the iridescent blue, is being taken from the flavoured ice and ‘given’ to the sky. This moment of transfer occurs in this metaphor via a feeling: delirious. It is the deliriousness that gives the metaphor its specificity and nuance. It makes it clear that the thing being drawn on from the flavoured ice is the quality of being heightened, artificial and also not quite real. It works so well because it makes the comparison much clearer and more precise. We’re left with no ambiguity about what aspects of the flavoured ice is being compared to the sky — the metaphor guides us in a way that is precise such that the recognition is immediate.