The poet is "at the end of [his] life." "Picture and book remain,/An acre of green grass/For air and exercise". He is losing his "strength of body". He finds that "imagination" and reason - "the mill of the mind" cannot find the truth. All he can hope for is "an old man's frenzy", a madness of loneliness and age. Only this will bring the truth to him.
4 stanzas of 6 lines each. The last two lines of each stanza rhyme. Each line is short. A certain pattern to the syllables, but the rhythm is broken and uneven, hardly melodious. Lines 2 and 4 of stanzas 3 and 4 rhyme.
Simple language in the first stanza, perhaps to echo simple desires. The language moves to the abstract in the second stanza: "temptation", "imagination", "the mill of the mind". There are literary references in the third stanza. Throughout the poem, the language is relatively simple and common.
Impersonal first stanza, entirely third person. Second and third stanza are first person and the fourth stanza returns to the impersonal. The imperative - "must I" echoes the "beat upon the wall" in the third stanza - this is an overall 'violent upheaval' stanza, the climax of the poem.
The tone is gentle and assenting in the first stanza. In the second stanza it becomes confessional, sharing the poet's inadequacies. In the third stanza the tone is angry, pleading, desirous, and in the fourth stanza transcendental, calm. The pinnacle of experience.
The mood seems resigned in the first stanza, resigned to death, to a quiet fading. The pace quickens in the second stanza. The mood is suddenly frenetic in the third stanza, desperate, questing, hankering. The fourth stanza has an exultant, transcendental mood.
Alliteration - "green grass", "life... loose", "mill... mind", "Myself must... remake".
Figures of Speech.
"Midnight", "life's end" - euphemisms for death. "Nothing stirs but a...