This poem stands in contrast to “The Divine Image” of the Songs of Innocence, and in fact, Blake’s original title for it was “The Human Image.” In it, Blake argues that human reason and abstract thinking lead to harm, because the virtues they extol require the existence of suffering. Pity presupposes poverty, while mercy assumes the existence of sorrow. He then continues with a litany of false virtues that arise from sin or vice: peace comes from mutual fear, love increases by selfishness, and care is the bait used by cruelty.
"The Human Abstract" keeps to an AABB couplet rhyme scheme throughout, invoking the childhood rhyming of Innocence. The first two stanzas are didactic, offering simple lessons in the unfortunate roots of human virtue. The third stanza begins a narrative starring "He" (a sort of Everyman), whose first act is to sit down and cry. The fourth stanza breaks the strict AABB rhyme pattern, with "shade" and "head" only barely rhyming while "Fly" and "Mystery" only rhyme if read similarly to "eye" and "Symmetry" from "The Tyger." This discord focuses the reader on the "Mystery," which is the only capitalized noun to be repeated in the poem, here even in the same stanza. This Mystery probably referrs to the "mystery religion" aspect of Christianity and in particular to the problem of suffering, and it hangs over the head of the crying man, but is itself devoured by the caterpillar and fly, which are agents of decay and death in Blake's poetry. The fifth stanza returns to the AABB rhyme scheme to finish the narrative, then the sixth stanza ends with a moralizing couplet: the search for the "Tree" of knowledge is found within the human mind.
An unnamed “he” grows humility only by watering the ground with tears borne of “holy fears.” This tree is the Mystery of Religion, and it grows quite tall and strong until “the Caterpillar and the Fly” eat at it. These two destroyers represent the clergy, a class often the subject of Blake’s criticism and scorn for their abuse of religious authority to their own selfish benefit and the harm of others. Once infested, the Mystery Tree bears fruit “of Deceit” and becomes the dwelling place of the raven, a harbinger of death. Blake claims that “The Gods of the earth and sea” sought to find this tree, or create religious experience through nature, but their efforts were in vain: this tree grows “in the human brain.”
As Bloom notes, the final two stanzas rely upon imagery found in Norse mythology. Odin hanged himself upon the world-tree Yggdrasil in order to gain knowledge of the runes. The fruit of Deceit is therefore not only an allusion to the tempting fruit in the Garden of Eden, but also the runes as a means of discerning the mystery of nature. The "Raven" is not only a death-related image, but also a symbol of Odin. The final stanza includes the gods' search throughout Nature to find "this Tree," a reference to the Norse gods' search for the mistletoe that killed one of their own, Balder. Their search, however, is in vain, since the murderous element is not part of Nature, but is inherent in the human mind.