Intended for healthcare professionals

History And Mystery

Retroactive prayer: a preposterous hypothesis?

BMJ 2003; 327 doi: (Published 18 December 2003) Cite this as: BMJ 2003;327:1465
  1. Brian Olshansky, director of cardiac electrophysiology (,
  2. Larry Dossey, executive editor2
  1. 1University of Iowa Hospitals, Iowa City, IA, USA
  2. 2Alternative Therapies in Health and Medicine, Santa Fe, NM, USA
  1. Correspondence to: B Olshansky

    Our Christmas 2001 issue included a study showing that retroactive prayer can improve health outcomes. But how are we to reconcile this result with our present understanding of the universe? Perhaps the answer lies beyond the superstring theories of today's physicists

    “We are not—even though we might prefer to be—the slaves of chronological time.”

    J B Priestley, Man and Time, 1978w1

    “If the existence of the present and future depends on the past, then the present and future should be in the past.”

    Nagarjuna (c150-c250), Fundamental Wisdom of the Middle Way c150-c250

    Studies involving intercessory prayer challenge the belief that thoughts and intentions cannot act remotely.14 Equally challenging is the possibility that human intentions and perceptions act outside the present.57 w3 What if prayer actually influences the person to whom it is directed, no matter how far removed? What if prayer affects the past?

    A study of retroactive prayer

    Leibovici published an intriguing study questioning conventional notions of time, space, prayer, consciousness, and causality.8 The randomised, controlled, double blind, parallel group study (prayer versus no prayer) included 3393 septic patients and considered the hypothesis that “retroactive” prayer, offered 4-10 years later, affects outcomes. Of the preselected outcomes, mortality was similar in both groups, yet length of stay in hospital and duration of fever were shorter with prayer (P = 0.01 and P = 0.04). Leibovici, with humour befitting his style, concluded that remote, retroactive intercessory prayer should be considered for clinical practice.


    Leibovici cautioned that a deep model of the physical world is essential for choosing hypotheses; practices that do not fit the model should not be tested in humans.9 “Would you believe a study that looks methodologically correct but tests something that is completely out of people's frame (or model) of the physical world?” …

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