What at first seems to be a simple reminiscing of a childhood memory, the Seamus Heaney's "Blackberries" conveys the speaker's concern about man's inability to control his desire through its literary elements. The speaker's use of imagery, allusion, and slant rhymes exhibits his belief that man is easily overcome by temptation.
As the speaker first describes the blackberry harvest, the underlying rape imagery suggests a parallel with man's ineptitude of self-control. The first berry is described as "glossy," conveying a sense of purity or virginity that the berry possesses. The speaker's diction shifts to carnal, as he uses words like "clot," "flesh," and "blood." The speaker has ravished the previously untouched berry in his quest to quench his "lust" and feed the "hunger" that has developed. The children in the story, however, show no restraint in collecting the berries, even despite the sense of guilt suggested by the "burn[ing] plate of eyes" that watches the children as they continue. A measure of the berry's grasp on the children is the statement that they disregarded pain, only to continue gathering. The speaker recognizes his failure to restrain his temptation when he alludes to Bluebeard, the fairy tale character who could not restrain from murdering his wives.
Additionally, the use of slant rhymes throughout the poem reflects the speaker's lack of control over temptation. At the sentences come close to rhyming, they do not quite have the necessary regulation to them, suggesting the speaker's lack of restraint. Moreover, the meanings of the lines that do have end rhymes are punctuated. For example, the children's massing of the berries in the "byre" results in an unattractive "fur" expressing the demise of the hunt.
The second part of the poem illustrates man's inability to control temptation, because as the children collected too many berries, the entire gathering is ruined.