In articles and books published over the last three decades, R.C. Harvey has argued that the essence of the comics medium lies in the interdependent juxtaposition of words and pictures. As Harvey writes in The Art of the Comic Book: An Aesthetic History, "One litmus test of good comics art is to ascertain to what extent the sense of the words depends on the pictures and vice versa [...] when words and pictures blend in mutual dependence to tell a story and thereby convey a meaning that neither the verbal nor the visual can achieve without the other, then the storyteller is using to the fullest the resources the medium offers him" (4).
Like lots of folks, I have problems with Harvey's juxtaposition theory. Harvey's tastes, for instance, are radically different from mine. In Comic Book, he cites a Bud Blake Tiger strip as an example of an outstanding combination of words and pictures, while comics I consider more valuable--like "American Splendor Assaults the Media," with its massive word balloon hovering over Robert Crumb's portrait of a feverish Harvey Pekar--would probably be too talky and not blendy enough for R.C.
I think that comics--like other texts--are multi-voiced and multi-faceted, and refuse to be reduced to an aesthetic prescription like word-picture interdependence.