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

Hearing hoofbeats outside, does one think of zebras?

Summary: Remember the medical maxim for diagnosis...Whenever you
hear hoofbeats outside, first think of horses—not zebras.

The original unimpeachable paper: When I saw my namesake’s paper
(Leonardo Leibovici, BMJ 2001;323:1450-1) two years ago, I assumed the
clue was that the paper was in the end-of-year (Xmas, Equinox) edition of
BMJ, which edition I always look forwards to. I suspected that the Editor
knew exactly how the paper’s research was done. We have given this paper,
as an example of putative unimpeachable research, to students in our
Science and Religion course. I believe that my namesake reported his work
precisely. I would like to sit down with him over coffee or beer, and say:
“Now, I ask you—as Leonard to Leonardo—will you admit privately that you
have yet to publish the umpteen similar experiments that you did, and
which did not reach any level of significance? Are you familiar with
Sokal’s exploits [Sokal and Bricmont]?” And I hope that, a la our
namesake’s Mona Lisa picture, Leonardo (and the Editor of BMJ) will give
only an inscrutable enigmatic smile, for it is more fun to leave the saga
as a mystery with which we can tease students.

Exuberant sequel: I first comment on the length of writing in the
paper “Retroactive prayer: a preposterous hypothesis” (BMJ 2003;327:1465-
8) and the rapid responses. I sincerely envy the authors in their writing
and explicative abilities, for personally I am no orator...but, as you
know me all, a plain blunt man. The paper with an abstract “Perhaps the
answer lies beyond the superstring theories of today’s physicists”, and
much of the ensuing correspondence, will be of interest to future
historians of science. They will ask why, just because there is no
immediate explanation for something, physicians—otherwise competent, one
prays—gleefully and exhuberantly adopt ideas which are but figments of the
imagination, at present. Physicians and physicists both believe in
Occam’s Razor: “Whenever you hear hoofbeats outside, first think of
horses—not zebras.” Physics is an ultimate achievement of the human
spirit, in that theory and experiment agree to within the width of a human
hair in Los Angeles, measured from New York (this best agreement is not,
as one might expect, in gravitation, but in quantum electrodynamics
[Kinoshita and Nio]). String theory is our best approach to a GUT (grand
unified theory); its proponents will agree that physics is ultimately
based on cruel experiment (also known as evidence-based), and that at
present, alas, there are no good experimental tests of the theory. To
posit “beyond the superstring theories” is, at a minimum, to go out on a
limb, build a house of cards, etc. So, to physicists, “Retroactive
prayer: a preposterous hypothesis” (with many of the comments) is
hilarious and makes wonderful reading [Hobson]. (Some of the comments,
however, do show an excellent understanding.) One thanks the Editor of
BMJ for not submitting the paper to a physics reviewer..see the last
phrase of the preceding paragraph.

Conclusion: Prayerfully pursuing Puck “Lord, what fools these mortals

I thank Dick Joyce (who co-authored the first controlled study on the
efficacy of prayer in medicine) and Som Tyagi for discussions.


Hobson, A. Physics : concepts and connections.Upper Saddle River, NJ
: Prentice Hall/Pearson Education, 2003. This is an excellent accessible
introduction to non-locality.

Kinoshita T., Nio M. Revised alpha^{4} Term of Lepton g-2 from the
Feynman Diagrams Containing an Internal Light-By-Light Scattering
Subdiagram. Physical Review Letters 2003; 90: 021803.

Sokal, A., Bricmont, J. Fashionable nonsense: postmodern
intellectuals' abuse of science. New York : Picador USA, 1999.

Competing interests:
None declared

Competing interests: No competing interests

13 February 2004
Leonard Finegold
Professor, Biophysics
Department of Physics, Drexel University, Philadelphia PA 19104, USA