of men amount to evidence in the case the poet is arguing to his dying father to resist the encroaching blackness as long as the old man can. Beyond just imploring his father to hold on, the repeated refrains at the end of the stanzas also function as a prayerful talisman whose exhortations to life and light are imbued with spiritual or psychic energy to reanimate or reinvigorate the perishable body.

Just as significant as the repeated final lines of each stanza, the first lines of the middle three stanzas repetition of different qualities of "men": the "wise," "good" and "wild." All of these types are alike in recognizing the insufficiency of a human lifespan to do, or say, or make all of the things that a person realizes are left undone when it is finally too late. Before the final stanza, when it becomes clear that the poem is specifically addressed to the poet's father, the poet introduces and supports the point about the universality of the dying regrets he wishes his father to be spared from.

The speaker of this poem utilizes repetition from the first stanza; the final line of that stanza implores his father to "rage, rage" against the process of dying. Repeating a word in quick succession is a literary technique called epizeuxis. The effect of this type of repetition is to establish a vehement sense of urgency. "Rage" is a particularly strong verb to use here; it connotes a sense of violence and anger. Thus, the speaker begs his father to bolster up the energy for a battle against death, refusing to simply slip gently away from life.

The final word in each stanza also exemplifies repetition, alternating between night and light. Night symbolizes death in this poem, and light represents life. Through this alternating repetition, life and death are inextricably linked to each other. The road of life must inevitably lead to death; however, the speaker issues a repeated command, saying, "Do not go gentle into that good night," beseeching his father to continue living. Though the speaker realizes that a metaphorical night must eventually come, he asks his father to hold on to the light for as long as possible.

The repetition of these symbols and phrases convey the depth of the speaker's love for his father. Unwilling to imagine a world without his father in it, the speaker is even willing to accept the "curse" of his father—as long as it conjures up enough strength for him to fight fiercely. The repetition helps to establish a tone of intimacy as the speaker begs his father not to leave him.

The repetition of the first and third lines of the poem impress the reader with the speaker's relative desperation that his father fight against death (we learn the narrator of the poem is speaking to his or her father in line 16). It sounds as though the speaker is trying to persuade his or her father that, although continuing to live might be painful or difficult, resisting death is the best thing, the right thing, to do. The speaker repeats these lines in the context of describing all different kinds of men—wise men, good men, wild men, and serious men (or men who are very near death, since "Grave" has two potential meanings here)—and all the different reasons that they choose to stay in "the light." This seems to be an attempt to convince the father that no one else goes "gentle into that good night," so neither should he.

In the poem "Do Not Go Gentle into That Good Night," the speaker desperately implores a loved one to fight against old age and death. The loved one in this instance is likely the poet's father, who, at the time the poem was published, was close to death, dying one year later.

The line "Do not go gentle into that good night" is repeated four times in the poem, as is the line "Rage, rage against the dying of the light." The fact that these lines are repeated so often emphasizes how desperate the speaker is for his father to fight for his life. This desperation is also emphasized by the fact that the poem begins with one of these lines and concludes with the other, meaning that the speaker's desperation is the first and last impression of the poem. Both lines are also written as imperative sentences, or orders, furthering the impression that the speaker is so desperate that he refuses to allow his father to do anything but rage and fight against his death.

The "good night" is of course a euphemistic reference to death. The fact that the speaker refers to death in this euphemistic way suggests that he is trying to comfort himself with the idea that when death does take his father, it will at least be gentle and comforting. It may even offer his father some respite from the pain and suffering of his life. The repetition of the "good night" euphemism emphasizes how much comfort the speaker needs to give himself and thus how desperate and upset he feels about his father's impending death.

In this villanelle by Dylan Thomas, the final line of each three-line stanza alternates between "Rage, rage against the dying of the light" and "Do not go gentle into that good night." The first line is "Do not go gentle into that good night," and the final line is "Rage, rage against the dying of the light." This results in each line being repeated four times. However, each time each line is used, it works into the flow of the argument of the words of the stanza. The lines are not merely appended as a disjointed refrain. 

Each stanza gives an example of the kind of person who does not go gentle into that good night and/or rages against the dying of the light. Wise men, good men, wild men, and grave men all stand as examples, according to the poet, to his father, whom the poet wishes would fight against his approaching death. Although to see his father resisting death might in one sense be a "curse" because it would be hard to observe, nevertheless the poet feels it would be a blessing because it would show the kind of spunk and spirit the poet thinks men should have when they leave this life.

The two repeated commands are two sides of the same coin and are parallel or roughly synonymous expressions. The way that one does not "go gentle" is by raging. Therefore, although each expression appears four times, the thought appears a total of eight times in the poem. Obviously such heavy repetition within a few lines creates a strong emphasis, revealing the poet's passion for his message. Thinking of the setting and the situation, a young man sitting at his father's deathbed, we can also imagine that the repetition is required in order to get through to a person who might be semi-conscious or even unconscious, hard of hearing, or suffering from some type of dementia. The repetition of "rage, rage" within the same sentence gives the sense of continuing and continuous rage; the poet wants his father to be able to sustain a valiant, spirited resistance over a period of time. On the other hand, the repetition of "good night" is a reminder for both the father and the son that the father's ultimate destination is not one to be unduly frightened of. At some point, they will say "good night" to each other, and the father will go into his final slumber. 

In his emotional and moving plea to his father to embrace life until the very end, the repetition of the lines cited above increase the intensity and personal meaning of Dylan Thomas's poem.

Despite the inevitability of death, Thomas as the speaker of this poem feels that by "raging against the light," or affirming life, his father can die with dignity as opposed to "going gently," or weakly.  Thomas's arrangement of his poem into a villanelle form also underscores the the intensity rhetorical argument of his work.  Thus, the repetition of lines as a rhetorical form adds emphasis and meaning to the argument.  And, because the villanelle's form resists narrative development, this form strengthens the speaker's insistence upon his father's affirmation of life.