Physician Dossey (Medicine and Meaning, 1991, etc.) continues to probe links between medicine and spirituality in this popular study of the healing power of prayer. Prayer heals? Hardly news in the religious world, where Hebrew Bible and New Testament alike attest to prayer's medicinal effects. But for science, it's a revelation, one confirmed by dozens of laboratory experiments that Dossey cites. Prayer can help with high blood pressure, asthma, heart attacks, headaches, and anxiety; moreover, it can alter enzyme activity, blood cell growth, and the germination of seeds. Dossey rejects the traditional Judeo-Christian notion of prayer as a relationship to a transcendental God, offering instead his own quasi-pantheistic view of prayer as a ``genuinely nonlocal event'' directed to the ``Absolute'' in all things. In any case, prayer apparently works: Even unconscious or dream prayer, it seems, can be effective. At the same time, prayers often remain unfulfilled, and Dossey blasts New Agers for preaching that illness is the patient's fault and that physical health always reflects spiritual health, pointing out that many saints have suffered from terrible physical or emotional maladies. An attitude of reverence and optimism is the best approach, he says, to spiritual and physical well-being. Not likely to sway hard-core materialists, especially when Dossey dips into the deep end by asserting that patients can rewrite their medical histories by ``intervening in subatomic processes in the past.'' Nonetheless, this raises new questions (Should you ask permission before praying for someone else? Should a physician pray for his patients?) about an old but little-studied phenomenon.