In the originality, comprehensiveness, and sheer energy of his analysis of the religious dimension of human experience, William Blake's artistic achievement is matched in Western literature only by that of Dante and Milton. Religion was, arguably, the primary theme and motive of all his art, poetic and pictorial. But to compare Blake's art with the work of other poets and painters soon makes clear that his own artistic program and vision differed strikingly from what is commonly understood to be the purpose of religious art. His poetry, and the illuminations that enrich it, only rarely are expressions of devotion. Although one catches glimpses of personal piety in his letters, and senses it in his more conventional pictorial art, Blake's illuminated verse is primarily social in its concerns, focusing on the historic and psychic origins of religious faith and on religion's influence on human behavior. Blake was convinced that religion profoundly affects every aspect of human life - political, economic, psychological, and cultural - and that its influence has generally not been a positive one. He detected flawed religious thinking at the root of most of the social disorders afflicting England in his time, and found that even the highest virtues associated with religion - “Mercy Pity Peace and Love” (E 12) - were routinely misconceived or manipulated for destructive ends.