Metaphors identify phenomena in a manner that is literally distinct from their realities. This allows a game of chess to become a ‘battle of wits’, enables the poet U. A. Fanthorpe to ‘choke the future back down our throats’ and justified Arthur C. Clarke's modelling of his alien ‘Overlords’ as the ‘shepherds’ of humankind in Childhood's End (1953). Metaphor creates a higher level of understanding by using elements of an older, already existent knowledge and placing it into an unfamiliar space, as with the typical Asimov observation that ‘Astronomers were queer ducks’. Both metaphor and metonymy are eloquent in SF, as authors experiment with the human mindset on planets populated with alien life forms and fantastic, unknowable cultures. As George Lakoff and Mark Turner suggest:

Given that metaphor is traditionally the product of imagination, it is interesting to note as an aside that even in the realm of science, usually the most quantifiable and concrete of disciplines, there is a place for such creative description: a ‘black hole’, for example, is neither black nor a hole – the term was chosen to communicate the fact that light and matter inevitably fall and are lost into these seemingly endless voids. In a similar fashion, the term ‘quantum leap’ has taken on the metaphorical value of meaning ‘a great stride forward’, when in fact it was originally coined to explain the abrupt transition of an atom or molecule from one quantum state to another – a very small transition at that scale. It is understandable, then, why SF, so often the fictional extrapolation of science, has taken both literary and scientific metaphors and romanticised them into an aggregation of tropes and dramatised scenarios. As an aspect of cultural and social structure, metaphor can also reveal many details about us, both as individuals in the metaphors we choose and as a society by the common recognition of the term.