Tennysonian Love: The Strange Diagonal by Gerhard Joseph (1969)
The book helped me understand more clearly a lot of what appeals to me in Tennyson (gee, I guess that's what this lit crit fad is all about, huh?)--his theme of "the tragic inevitability of change and of human mortality." (The discussion of "Tears, Idle Tears" is especially good. Gerhard traces the conflicts in Tennyson's depictions of love (in the broadest sense), between sensuousness and idealism, between classic myth and Christianity, between "hearth and home" and the "fatal woman." The last chapter, "The Myth of Western Love" (discussing Idylls of the King), talks about why the stories of Arthur/Guinevere/Lancelot and Tristan/Iseult/Mark were popular topics for the Victorians, which in turn made me appreciate T.H. White's The Once and Future King (one of my all-time favorites) in a new way.
The lasting significance of the Idylls of the King is the comprehensive way in which it outlines the most basic of human tragedies, the personal and social dislocations that arise from man's passion to transcend mutability and mortality. Muted in our own sensibility is the extreme aversion to the human body that certain historical periods have stressed in the sense/soul division of both Platonic eros and Christian agape. But man's fleshly nature is still his most pesistent reminder of change and death; his heroic drive to elude these twin terrors is as intense as ever; and the certainty of their triumph over his best efforts is as much the occasion of idle tears as it has always been. Whether or not we insist upon translating into a contemporary idiom the Platonic/Christian terminology (a marriage-war between sense and soul) in which Tennyson couches these themes, we cannot escape the continuing relevance for our restless, questing selves of Tennyson's vast Arthurian tapestry.