More rumblings about the imminent implosion of Planet Earth, with sketchy survival blueprints, this time from two California New Age powerhouses. Ehrlich (The Machinery of Nature, 1986) and Ornstein (Multimind, 1986) argue that ""the human mental system is failing to comprehend the modern world,"" a sure recipe for disaster. What's the problem? Our minds perform as they did 20,000 years ago, favoring quick reactions to meet short-term problems--a charging saber-toothed tiger, for instance--in a stable environment. But now we need ""slow reflexes"" able to cope with long-term challenges, such as acid-rain and a depleted ozone layer. After rehashing current thinking about human evolution and our progressive destruction of the environment, the authors blast some sacred modern icons--medicine, psychotherapy, and orthodox religion, in particular--for clinging to ineffective or outmoded approaches. What's the solution? A gamut of proposals, some common-sensical (an educational system that emphasizes the three E's--ecology, evolution, and energy), some downright bizarre (an American monarchy to free politics of inappropriate emotions; Ronald Reagan, the authors contend, would have made a far more competent king than president). Another dire weather forecast for the human race, with some intriguing suggestions for letting the sunshine in. Unlike most such manifestos, this relies on careful argument and historical precedent, and thus might just covert some hard-line ""old-mind"" types.