We don't normally associate austerity and self-effacing understatement with Texas, especially with free-wheeling Houston—city of oil, money, bayous, sports and urban cowboys. But courtesy of one great immigrant couple from France, John (1904-73) and Dominique (1908-97) de Menil, this city with no zoning laws possesses a locus of spiritual and artistic calm in the middle of a tranquil, verdant, in-town residential neighborhood abutting the University of St. Thomas.