The poetic image is not a static thing. It lives in time, as does the poem. Unless it is the first image of the poem, it has already been prepared for by other images; and it prepares us for further images and rhythms to come. Even if it is the first image of the poem, the establishment of the rhythm prepares us — musically — for the music of the image. And if its first word begins the poem, it has the role of putting into motion all the course of images and music of the entire work, with nothing to refer to, except perhaps a title.
p. 32 - The Life of Poetry (1949)