Final answer:
In 'Invictus,' William Ernest Henley develops a theme of courage using his own experiences to emphasize resilience and determination, exemplified by the declarative lines at the poem's conclusion.
Step-by-step explanation:
In Invictus by William Ernest Henley, the poem's speaker develops a theme of courage in the face of adversity. Henley, who faced significant health challenges, uses his own experiences to convey resilience and determination. For example, the lines "I am the master of my fate: / I am the captain of my soul," declare an unwavering command of one's own life, suggesting that true bravery comes from within. The poem's consistent meter and rhyming couplets serve as a metaphor for the speaker's composed and defiant stance against life's struggles. This textual evidence, framed by the speaker's perspective, underlines the theme that steadfastness and courage are vital to withstanding the trials of life.