Final answer:
Seamus Heaney uses an oxymoron to highlight the wind's invisible yet powerful nature in a storm, suggesting that it shouldn't be feared. This figure of speech reveals the complex duality of nature, indicative of Heaney's poetic themes.
Step-by-step explanation:
Seamus Heaney, an acclaimed poet, often uses figurative language to convey complex ideas and emotions in his poetry. An oxymoron is a figure of speech that combines two contradictory terms. You mentioned that Heaney uses an oxymoron to suggest that the wind is invisible and therefore should not be feared despite the raging storm.
This literary device can emphasize the duality of nature - its capacity to be both frightening yet innocuous, suggesting a deeper reflection on the contrast between perception and reality. For example, describing the wind as a 'silent scream' would highlight its invisible, yet forceful presence, encapsulating the idea of an unseen but powerful force of nature.
The use of oxymorons in literature often challenges readers to explore these contradictions, leading to a more profound understanding of the theme or the subject matter in question. Heaney's poetry frequently explores the relationship between humans and nature, and by portraying the wind as something not to be feared despite its power, he might be suggesting a respect for the natural world and an acceptance of its inherent contradictions.