Jorge Guillén's literary criticism makes a case for the “sufficiency” of poetic language, its capacity to measure up to the richness of its creator's inner experience. To define the attitudes toward language that underlie his poetics, this essay reconstructs his argument in Language and Poetry, a series of authoritative lectures on major Spanish poets in which Guillén attempts to refute linguistic skepticism. His advocacy of sufficient language meets its test in his own poetry in Cántico. Although critics have traditionally viewed his theory as mimetic, his poems also reveal an awareness of linguistic mediation that undercuts his seemingly naive faith in the power of the poetic word.