Ashton, whose approach to modern-artist biography is a straightforward and sometimes hushedly respectful one, quickly presents the touchstones of Rothko's brooding career: the lifelong quest for the ""single tragic idea,"" which sent him back again and again to reading Aeschylus and Kierkegaard; the writhings between ethics and aesthetics (especially in the late 1930s); a brisk, pointed analysis of what Rothko saw--and was moved by--in Fra Angelico, a crucial influence; the biomorphic symbolisms of the late-'40s canvases; and a trim descriptive attempt to convey what Rothko's glowing bars of spectral color (his 1950s classics) were trying to mean. Still, Rothko-the-man remains largely closed-off from us in Ashton's summary. We get testimony about his cranky insistences on the sublime, about (on the other hand) his willful and unconvincing personal materialism, his bleak moods, his escape into ineffability. But Ashton doesn't ever illuminate the psychological sources of Rothko's life and work. Instead she provides rafts of literary and philosophical corollaries; in the last chapters especially, there's an almost comic rapid-fire succession of quotes from Joyce, MallarmÃ‰, the monastic writer Theophillus, Pascal, Phillipe Sollers, and Heidegger, establishing Rothko as a man of existential concerns--yet failing to provide original insight into this painter's monumental treatment of his own, introspective traumas. Skillful as description, then, but too reverent and un-probing as analysis: Ashton lights Rothko up as if by strobe, in small bursts of tangential authority.