SAL SI PUEDES by Peter Matthiessen. 372 pages. Random House. $6.95.
Every modern saint can be seen as a more than worthy character in search of a more than worthy author. In Peter Matthiessen, Mexican-American leader Cesar Chavez would seem to have found the perfect biographer. As a novelist (At Play in the Fields of the Lord), Matthiessen has a proven taste for mystics, especially from Latin America. As a naturalist (Wildlife in America), he has shown true indignation at the greedy exploitation of man and nature. Small wonder that in this book he begins by investing Chavez's selfless fight against the...