One of the primary aspects of the Romantic tradition that is strongly expressed in the poetry of Blake is the use of nature to metaphorically emphasize the metaphysical attributes of humanity. Many Romantic philosophers of the nineteenth century used the imagery of nature to attempt to reveal the inner depths of the human condition. Many others lamented what they saw as a loss of the arcadian purity of a past in which human beings lived in harmony with their environments.
"Proverbs of Hell" is a poem that is composed of a number of stand-alone aphorisms. Blake intends each to reveal some kind of moral truth about the soul and the human condition. For example, he says that
No bird soars too high, if he soars with his own wings
early in the poem. In this line, the bird is a metaphorical representation of the ambitious person. Just as a bird successfully soars (note the pathos that is evident in the use of this particular verb) if he uses his own wings, no human accomplishment is too great if one achieves it with their own hands. In another set of lines, Blake contends that
As the caterpillar chooses the fairest leaves to lay her eggs on, so the priest lays his curse on the fairest joys.
Again, he is using the imagery of nature to make commentary on the general condition of mankind. In this particular instance, he waxes philosophical on the joys that humans can feel and how the priests can easily destroy them. Just as the caterpillar’s larvae will ultimately eat the leaves that they are laid on, the false prophecies of the corrupt priest will eat away at and erode the greatest joys that humankind can partake in. The symbolic reference to nature was very common within the Romantic tradition. Blake adeptly utilizes metaphor and imagery to reveal certain inner workings of the human soul.