The devil is an angel too.

Read in light of Unamuno’s recurring preoccupation with spiritual conflict and moral ambiguity, the line compresses a theological paradox into a moral warning: evil is not always alien or monstrous, but can be continuous with what appears luminous, elevated, or “angelic.” By reminding us that the devil is (in traditional Christian myth) a fallen angel, the phrase suggests that corruption can arise from within the highest aspirations—intellect, pride, purity, even faith—and that the boundary between sanctity and perdition is unstable. The effect is to unsettle simplistic moral binaries and to urge vigilance toward the seductive, idealized forms that wrongdoing can take.