In Plato's "Symposium," desire (eros) is the philosophical motor of ascent from the beautiful body to the Form of Beauty itself, and this Platonic erotics runs through Dante's love poetry and his use of Beatrice as the vehicle of spiritual ascent; Lacan's psychoanalytic philosophy of desire — desire as constitutively lacking its object, always displaced onto a new object in a metonymic chain — informs much contemporary poetry that treats longing not as a temporary condition to be satisfied but as a permanent structure of the subject; A poet writing about unrequited love might invoke Spinoza's philosophy of desire (desire as the essence of the human being, the conatus or striving that constitutes the self) to argue that the desire itself, not its satisfaction, is the fundamental human reality; Deleuze and Guattari's reconceptualization of desire — not as lack but as productive, affirmative, world-making — has influenced poets who celebrate desire not as a painful absence but as a positive creative force; Sappho's lyric fragments are the founding texts of the poetry of desire, and their philosophical sophistication — in staging the split self, the symptoms of eros, the objectification of the beloved — makes them philosophical documents as well as poems; Anne Carson's "Eros the Bittersweet" is simultaneously a philosophical treatise on desire and a book deeply influenced by poetic tradition, arguing that desire requires the gap, the missing piece, to sustain itself — and that poetry and desire share this structure