One of the main subjects of “Do Not Go Gentle into That Good Night” is retrospection, the process in which the aged look back and reflect upon their lives. The central portion of the poem—the second through fifth stanzas—consists of four vignettes or parables, each representing a different type of person arriving at death and attaining some insight about their life’s journey.

The second stanza describes “wise men,” those who have lived a life of the mind. Their conflict arises from the fact that, on the one hand, they comprehend death and its necessity—they “know dark is right”—but, on the other hand, they grasp the ineffectuality of their lives. Despite their keen ideas, “their words had forked no lightning”; their harsh lesson is that they have made no tangible impact which might offer some consolation in the face of death. Thus, the speaker urges them not to “go gentle into that good night.”

The third stanza tells of “good men,” those whose lives have been conducted in the service of moral aims. As in the second stanza, Thomas summons a natural metaphor, comparing life to “a green bay.” The lesson of the “good men” is that their good works are in fact “frail deeds” that may have “danced” on the water. There is an ambiguity to this moment which hinges on the word “crying”: these men are “crying how bright / Their frail deeds might have danced.” At one level, their cry is one of self-congratulatory denial, but on a deeper level, it is a cry of anguish, a recognition that their efforts have been as insubstantial as reflections on the surface of the sea.

The fourth and fifth stanzas depict “wild men” and “grave men,” respectively. The former are depicted as people who have lived lives of pleasure and joy but realize, “too late,” that life is fleeting and brief. The “grave men,” possessed of a “blinding sight,” achieve, upon their deaths, the belated realization that joyful, blazing vision is possible.

Although these lessons differ, they are all difficult to face and they all arrive “too late” to be of practical use. And the poem does not offer a positive model for existence to hold up against these flawed lives. In this way, the poem does not prescribe or moralize; after all, to “rage” against death is more catharsis than solution. Rather, it offers a description of the human condition, telling of the uncertainty and imperfection of life and of the suffering of age and death.