One of the main themes in Walcott's poem "Sabbaths, W.I." is the theme of poverty. In the second stanza of the poem, the speaker refers to poverty as "the incurable sore." This metaphor suggests that poverty is a wound that can never be healed and thus a wound that is permanently debilitating, painful, or even fatal.
Another theme in the poem is the death of the natural world. The speaker describes a "dead lizard turning blue as stone" and rivers that have "forgot[ten] the old music." The simile in the first quotation suggests that the natural world, embodied here by the lizard, has lost all of its life. It has lost all of its warmth and all of its color. In the second quotation, the river is personified as a person who once was familiar with music but has now forgotten. The implication here is that the natural world has lost its rhythm and its beauty. The idea that the natural world has died is suggested elsewhere in the poem, too, whether it be with the "hillsides like broken pots" or the "ferns that stamped their skeletons on the skin."
A third major theme in the poem is the theme of lethargy and melancholia. In the opening line of the poem, the speaker describes "villages stricken with the melancholia of Sunday." Sunday is a day which marks the end of the weekend and also heralds the beginning of the working week. It is also the day before children go back to school. Sunday is thus a day which connotes lethargy and a degree of melancholia. At the end of the poem, the speaker repeats five times the words "those Sundays." The purpose of this repetition is to emphasize the lethargy and melancholia connoted by Sunday. The idea is that in these villages, life seems slow, boring, and lifeless. This idea is emphasized when the speaker says that in these villages, "the lights at the road's end were an occasion." The lifelessness of the villages is also, of course, reflected in the images throughout the poem which suggest the death of nature.