The quality of "The Truly Great" that the narrator discusses in the first stanza is inspiration. These great individuals remember "the soul's spirit"—that is, they are in touch with the passion of creation that comes from the soul. The truly great come from a type of eternal place where the sun is always shining. They speak of things that come from the soul, and their lips are "touched with fire," meaning they overflow with passionate belief in what they do and say. These great souls are filled with overwhelming desire, and they have passions that they want to fulfill. In the second stanza, the narrator says that the blood of these great people comes from "ageless springs," meaning there is something eternal and everlasting about the passion and inspiration of the truly great.
The first stanza of "The Truly Great" by Stephen Spender consists of eight lines of unrhymed free verse. The first person narrator speaks a sort of interior monologue, reflecting on " those who were truly great."
The most interesting feature of this poem is that Spender's narrator considers "greatness" as defined by personality rather than action. In other words, his "truly great" are not those who accomplish great deeds, but those with a specific sort of character, one that burns with a Paterian "hard, gemlike flame."
The description in the first stanza, which does appear very heavily influenced by Pater's essays on Platonism, focuses on the souls of the great in the womb, who remember their history of direct apprehension of the One or God before the soul descends into the body, according the Plato's middle dialogues. This remembrance inspires the great to live their lives in an intense and inspired fashion, always remembering and striving towards great ideals.