RIVERWALKING: Reflections on Moving Water by Kathleen Dean Moore. (Lyons and Burford: $19.95; 176 pp.) "Sometimes, in a desert landscape, a landscape without consciousness, emptier of intellect than any other landscape I have ever seen, I think I can feel emotion lying like heat on the surface of the sand. . . . Moore is a professor of philosophy at Oregon State University. And she has walked in rivers all her life; first with her naturalist father, then with her husband and children. "There is one thing you will need to learn," a philosophy professor admonished her in college, "philosophy is not about life. Philosophy is about ideas. Life and ideas are not the same." Moore may have paid dutiful respect to this authoritative statement, but her own book disproves that effort. Memories of her father, postponed sadness over her mother's death when she was still in college are inextricably interwoven with observations of water, herons and "scalloped clouds" that "blew across the face of the moon." This is a meditation on doing and thinking, beginning with rivers.