"The Raven" by Edgar Allan Poe is a poem written in the first person. the narrator is a student studying late at night and morning his lost love, Lenore. He describes himself as "weak and weary." The tone of the narration in the first few stanzas suggests that the narrator is unreliable and sees everything through the lens of his own emotions, a form of projection know to literary critics as "the pathetic fallacy."
When the narrator sees the raven, he reflects on its significance. His rational mind realizes that it is probably simply an escaped pet and its repetition of the word "nevermore" perhaps just an odd habit of imitation or simply a raven's squawk being refracted through the lens of the narrator's melancholy.
As the narrator becomes increasingly absorbed in his own despair he begins almost to hallucinate, describing the bird as a "grim, ungainly, ghastly, gaunt, and ominous bird of yore."
As a work of psychological portraiture, the poem informs readers of two things. The first is the way depression and despair can create a vicious cycle in which every external event is interpreted as something that fuels more despair, paranoia, and anxiety. The second main commentary on human nature of the poem is to suggest that emotions can overwhelm rational capacity.