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Above all, do no harm. (how the Hippocratic oath applies to scientists)
Author/s: Stephen Jay Gould
Long, stagnant, and costly wars tend to begin in idealistic fervor and end in cynical misery. Our own Civil War inflicted a horrendous toll of death and seared our national consciousness with a brand that has only become deeper with time. In 1862, the Union Army rejoiced in singing the year's most popular ditty:
Yes we'll rally round the flag,
boys, we'll rally once again
Shouting the battle cry of Freedom,
We will rally from the hillside,
we'll gather from the plain,
Shouting the battle cry of Freedom...
So we're springing to the
call from the East and from the West
And we'll hurl the rebel crew
from the land we love the best.
By 1864, Walter Kittredge's "Tenting on the Old Camp Ground" had become the favorite song of both sides. The chorus, with its haunting (if naive) melody, summarizes the common trajectory:
Many are the hearts that
are weary tonight,
Wishing for the war to cease;
Many are the hearts
looking for the right
To see the dawn of peace.
But nothing can quite match the horrors of World War I, the conflict that the French still call la grande guerre (the Great War) and that we labeled "the war to end all wars." America entered late and suffered relatively few casualties as a consequence--so we rarely appreciate the extent of carnage among soldiers or the near certainty of death or serious maiming along lines of stagnant trenches, where men fought back and forth month after month to take, and then lose again, a few shifting feet of territory. I feel chills up and down my spine whenever I look at the "honor roll" list posted at the village green or main square in small towns in England and France. Above all else, I note the much longer lists for 1914-18 (often marking the near extermination of a generation of males) than for 1941-45. Rupert Brooke could write his famous poems of resignation and patriotism because he died in 1915, during the initial blush of enthusiasm:
If I should die, think only this of me:
That there's some corner
of a foreign field
That is for ever England. There shall be
In that rich earth a richer
His fellow poet Siegfried Sassoon, who survived and became a pacifist (a condition first attributed to shell shock and leading to his temporary confinement in a sanatorium), caught the drift of later realism:
And when the war is done
and youth stone dead
I'll toddle safely home
and die--in bed.
Sassoon met Wilfred Owen, the third member of this famous trio of British war poets, in the sanatorium. But Owen went back to the front, where he was killed exactly one week before Armistice Day. Sassoon published his friend's single, slim volume of poetry, containing the most famous and bitter lines of all:
What passing-bells for these
who died as cattle?
Only the monstrous anger
of the guns.
Only the stuttering rifles'
Can patter out their nasty orisons.
Among the horrors of World War I, we remember not only the carnage caused by conventional tactics of trench warfare with bombs and bullets but also the first effective and large-scale use of newfangled chemical and biological weapons--beginning with a German chlorine gas attack along four miles of the French line at Ypres on April 22, 1915, and ending with 100,000 tons of various chemical agents used by both sides. The Geneva Protocol, signed in 1925 by most major nations (but not by the United States until much later), banned both chemical and biological weapons--a prohibition followed by all sides in World War II, even amid some of the grimmest deeds in all human history. (A few violations have occurred in local wars: by the Italian army in Ethiopia in 1935-36, for example, and in recent wars in Iran and Iraq.) The Geneva Protocol prohibited "the use in war of asphyxiating, poisonous or other gases, and of all analogous liquids, materials or devices."
A recent contribution to Nature (June 25, 1998), the leading British professional journal of science, recalled this episode of twentieth-century history in a remarkable letter entitled "Deadly relic of the Great War." The opening paragraph reads:
The curator or a police museum in Trondheim,
Norway, recently discovered in his
archive collection a glass bottle containing
two irregularly shaped sugar lumps. A
small hole had been bored into each of these
lumps and a glass capillary tube, sealed at
its tip, was embedded into one of the lumps.
A note attached to the exhibit
translated as follows: "A piece of
sugar containing anthrax bacilli,
found in the luggage of Baron
Otto Karl von Rosen, when he
teas apprehended in Karasjok in
January 1917, suspected of espionage
Modern science to the rescue, even in pursuit of a mad scheme that came to naught in a marginal and forgotten outpost of a great war--the very definition of historical trivia, however intriguing, in the midst of great pith and moment. The authors of the letter removed the capillary tube and dumped the contents ("a brown fluid") onto a petri dish. Two columns of conventional scientific prose then detailed the procedures followed, with all the usual rigor of long chemical names and precise amounts: "After incubation, 200 [micro]1 of these cultures were spread on 7% of horse-blood agar and L-agar medium identical to L-broth but solidified by the addition of 2% Difco Bacto agar]." The clear results could be stated more succinctly, as the authors both grew some anthrax bacilli in their cultures and then confirmed the presence of DNA from the same organism by PCR (polymerase chain reaction for amplifying small amounts of DNA to levels that can be analyzed). They write: "We therefore confirmed the presence of B. anthracis [scientific name of the anthrax bacillus] in the specimen by both culture and PCR. It proved possible to revive a few surviving organisms from the brink of extinction after they had been stored, without any special precautions, for 80 years."
But what was the good baron, an aristocrat of German, Swedish, and Finnish extraction, doing in this forsaken area of northeastern Norway in the middle of winter? Clearly up to no good, but to what form of no good? The authors continue:
When the Sheriff of Kautokeino, who was
present at the group's arrest, derisively
suggested that he should prepare soup from
the contents of the tin cans labeled "Svea
kott" (Swedish meat), the baron felt
obliged to admit that each can actually
contained between 2 and 4 kilograms of
The baron's luggage also yielded some bottles of curare, various microbial cultures, and nineteen sugar cubes, each containing anthrax. The two cubes in Trondheim are, apparently, the only survivors of this old incident. The baron claimed that he was only an honorable activist for Finnish independence, out to destroy supply lines to Russian-controlled areas. (Finland had been under loose control of the Russian czar and did win independence after the Bolshevik revolution.) Most historians suspect that he was actually working for the Germans, who had authorized a program for infecting horses and reindeer with anthrax to disrupt the transport of British arms (on sleds pulled by these animals) through northern Norway.
The baron, expelled after a few weeks in custody, never carried out his harebrained scheme. The authors of the Nature letter, Caroline Redmond, Martin J. Pearce, Richard J. Manchee, and Bjorn R Berdal, have inferred his intent:
The grinding of the sugar and its glass
insert between the molar teeth of horses
would probably result in a lethal injection
as the anthrax spores entered the body,
eventually facilitated through the small
lesions produced in the wall of the
alimentary tract by the broken glass. It is
not known whether reindeer eat sugar
lumps but presumably the baron never had
the chance to carry out this piece
As anthrax cannot be transmitted directly from animal to animal, the scheme probably would not have worked without a large supply of sugar cubes and very sweet teeth in the intended victims. But the authors do cite a potential danger to other participants: "However, if the meat from a dying animal had been consumed without adequate cooking, it is likely that human fatalities from gastrointestinal anthrax would have followed." The authors end their letter with a frank admission:
This small but relatively important episode
in the history of biological warfare is one of
the few instances where there is
confirmation of the intent to use a lethal
microorganism as a weapon, albeit 80 years
after the event. It did not, however, make
any significant difference to the course of the
We may treat this botched experiment in biological warfare as light relief in a dark time, but the greatest evils often begin as farcical and apparently harmless escapades, while an old motto cites eternal vigilance as the price of liberty. If Hitler had been quietly terminated after his ragtag band failed to seize local power in their Beer Hall Putsch of 1923 in Munich--even the name of this incident marks the derision then heaped on the protagonists--the history of our century might have unfolded in a much different, and almost surely happier, manner. Instead, Hitler spent a mere nine months in jail, where he wrote Mein Kampf and worked out his grisly plans.
We humans may be the smartest objects that ever came down the pike of life's history on earth, but we are outstandingly inept about certain issues, particularly when our emotional arrogance joins forces with our intellectual ignorance. Our inability to forecast the future lies foremost among these ineptitudes--not, in this case, as a limitation of our brains, but more as a principled consequence of the world's genuine complexity and indeterminism. We could go with this flow, but our arrogance intercedes, leading us to promote our ignorant intuitions into surefire forecasts about things to come.
I know only one antidote to the major danger arising from this incendiary mixture of arrogance and ignorance. Given our inability to predict the future, particularly our frequent failures to forecast the later and dire consequences of phenomena that seem impotent, or even risible, at their first faltering steps (a few reindeer with anthrax today, an entire human population with plague tomorrow), moral restraint may represent our only sure salvation. The wisdom of the Geneva Protocol lies in understanding that some relatively ineffective novelties of 1925 might become the principal horrors of a not-so-distant future. If such novelties can be nipped in the bud of their early ineffectiveness, we may be spared. We need only remember the legend of Pandora to recognize that some boxes, once opened, cannot be closed again.
The good sense in this vital form of moral restraint has been most seriously and effectively challenged by scientists who stand at the cutting edge of a developing technology and therefore imagine that they can control, or at least accurately forecast, any future developments. I dwell in the camp of scientists, but I want to illustrate the value of moral restraint as a
counterweight to dangerous pathways forged either by complacency or active pursuit and fueled by false confidence about forecasting the future.
I told a story about aristocratic bumbling with ineffective biological weapons in World War I--but we might be in quite a fix today if we had assumed that this technology could never transcend such early ineptitude, and if we had not worked hard for international restriction. But a much deeper lesson may be drawn from the other innovative, and much more effective, technology of chemical warfare in World War I. The primary figure for this lesson became one of the founders of my own field of modern evolutionary biology--J. B. S. Haldane (1892-1964), called "the cleverest man I ever knew" by Sir Peter Medawar, who was certainly the cleverest man I have ever known.
Haldane mixed so many apparently contradictory traits into his persona that one word stands out in every description of him I have ever read: enigma. He could be shy and kind or blustering and arrogant, elitist (and viciously dismissive of underlings who performed a task poorly) or egalitarian. (Haldane became a prominent member of the British Communist Party and wrote volumes of popular essays on scientific subjects for their Daily Worker. Friends, attributing his political views to a deep personal need for iconoclastic and contrarian behavior, said that he would surely have become a monarchist if he had lived in the Soviet Union.) Haldane held no formal degree in science but excelled in several fields, largely as a consequence of superior mathematical ability. He remains most famous, along with R. A. Fisher and Sewall Wright, as one of the three founders of the modern theory of population genetics, especially for integrating the previously warring concepts of Mendelian rules for heredity and Darwinian natural selection.
But a different contradiction motivates Haldane's appearance as the focus of this essay. Haldane, a man of peace and compassion, adored war--or at least his role on the front lines in World War I, where he was twice wounded (both times seriously) and mighty lucky to come home in one piece. Some people regarded him as utterly fearless and courageous beyond any possible call of duty; others, a bit more cynically perhaps (but also, I suspect, more realistically), viewed him as a latter-day Parsifal--a perfect fool who survived in situations of momentary danger (usually encountered as a result of his bravado and appalling recklessness) by a combination of superior intelligence joined with more dumb luck than any man has a right to expect. In any case, J. B. S. Haldane had a good war--every last moment of it.
He particularly enjoyed a spell of trench warfare against Turkish troops near the Tigris River, where, away from the main European front and unencumbered by foolish orders from senior officers without local experience, men could fight mano a mano (or at least gun against gun). Haldane wrote: "Here men were pitted against individual enemies with similar weapons, trench mortars or rifles with telescopic sights, each with a small team helping him. This was war as the great poets have sung it. I am lucky to have experienced it." Haldane then offered a more general toast to such a manly occupation: "I enjoyed the comradeship of war. Men like war because it is the only socialized activity in which they have ever taken part. The soldier is working with comrades for a great cause (or so at least he believes). In peacetime he is working for his own profit or someone else's."
Haldane's contact with chemical warfare began in great disappointment. After the first German gas attack at Ypres, the British War Office, by Lord Kitchener's direct command, dispatched Haldane's father, the eminent respiratory physiologist John Scott Haldane, to France in a desperate effort to overcome this new danger. The elder Haldane, who had worked with his son on physiological experiments for many years, greatly valued both J. B. S.'s mathematical skills and his willingness to act as a human guinea pig in medical experiments (an ancient tradition among biologists and a favorite strategy of the elder Haldane, who never asked his son to do anything he wouldn't try on himself). So J. B. S., much to his initial disgust, was pulled off the front lines he loved so well and into a laboratory with his father.
J. B. S. already knew a great deal about toxic gases, primarily through his role as father's helper in self-experimentation. He recalled some early work with his father on firedamp (methane) in mines:
To demonstrate the effects of breathing
firedamp, my father told me to stand up
and recite Mark Antony's speech from
Shakespeare's Julius Caesar, beginning
"Friends, Romans, countrymen." I soon
began to pant, and somewhere about "the
noble Brutus" my legs gave way and I
collapsed on to the floor, where,
of course, the air was all right.
In this way I learnt that
firedamp is lighter than air
and not dangerous to breathe.
(Have you ever read a testimony more faithful to the stereotype of British upper-class intellectual dottiness?)
The Haldanes, pere et fils, led a team of volunteer researchers in vitally important work (no doubt saving many thousands of lives) on the effects of noxious substances and the technology of gas masks. As always, they performed the most unpleasant and dangerous experiments on themselves. J. B. S. recalled:
We had to compare the effects on ourselves
of various quantities, with and without
respirators. It stung the eyes and produced a
tendency to gasp and cough when breathed.
. . . As each of us got sufficiently affected
by gas to render his lungs duly irritable,
another would take his place. None of us
was much the worse for the gas, or in any
real danger, as we knew where to stop, but
some had to go to bed for a jew days, and I
was very short of breath and incapable of
running for a month or so.
Thus, we cannot deny Haldane's superior knowledge or his maximal experience in the subject of chemical warfare. He therefore becomes an interesting test for the proposition that such expertise should confer special powers of forecasting--and that the technical knowledge of such people should therefore be trusted if they advocate a path of further development against the caution, the pessimism, even the defeatism of others who prefer moral restraint upon future technological progress because they fear the power of unforeseen directions and unanticipated consequences.
In 1925, as nations throughout the world signed the Geneva Protocol to ban chemical and biological warfare, J. B. S. Haldane published the most controversial of all his iconoclastic books: a slim volume of eighty-four pages, based on a lecture he had given in 1924 entitled Callinicus: A Defense of Chemical Warfare. (Callinicus, a seventh-century Jewish refugee in Constantinople, invented Greek fire, an incendiary liquid that could be shot from siphons toward enemy ships or troops. The subsequent flames, almost impossible to extinguish, helped save the Byzantine Empire from Islamic conquest for several centuries. The formula, known only to the emperor and to Callinicus's family, who held an exclusive right of manufacture, remained a state secret and still elicits controversy among scholars of warfare.)
Haldane's argument can be easily outlined. He summarized the data, including and death tolls and casuality rates, from gas attacks in World War I and proclaimed the results more humane than the consequences of conventional weaponry.
A case can be made out for gas
as a weapon on humanitarian
grounds, based on the very small
proportion of killed to casualties
from gas in the War, and
especially during its last year
[when better gas masks had
been made and well
Haldane based this conclusion on two arguments. He first listed the chemical agents used in the war and branded most of them as not dangerous for having only transient effects (making the assumption mat temporarily insensate soldiers would be passed by or humanely captured rather than slaughtered). The few chemicals that could induce more permanent harm--mustard gas, in particular--are both hard to control and relatively easy to avoid, with proper equipment. Secondly, he called upon his own frequent experience with poison gases and stated a strong preference for these agents over his equally personal contact with bullets:
Besides being wounded, I have been buried
alive, and on several occasions in peacetime
I have been asphyxiated to the point of
unconsciousness. The pain and discomfort
arising from the other experiences were
utterly negligent compared with those
produced by a good septic shell wound.
Haldane therefore concluded that gas, for being both effective as a weapon and reasonably humane in causing few deaths relative to the number of temporary incapacitations, should be validated and further developed as a primary military tactic:
I certainly share their [pacifists'] objection
to war, but I doubt whether by objecting to
it we are likely to avoid it in
future, however lofty our motives
or disinterested our conduct ....
If we are to have more wars, I
prefer that my country should be
on the winning side .... If it is
right for me to fight my enemy
with a sword, it is right for me to
fight him with mustard gas; if the
one is wrong, so is the other.
I do not flinch before this last statement from the realm of ultimate Realpolitik. The primary and obvious objection to Haldane's thesis in Callinicus--not only as raised by me in the abstract in 1998 but also as advanced by Haldane's numerous critics in 1925--holds that, whatever the impact of poison gas in its infancy in World War I (and I do not challenge Haldane's assessment), unrestrained use of this technology may lead to levels of effectiveness and numbers of deaths undreamed of in earlier warfare. Better the devil we know best than a devil seen only as an ineffective baby just introduced into our midst. If we can squelch this baby now, by moral restraint and international agreement, let's do so before he grows into a large and unstoppable adult potentially far more potent than any devil we know already.
(I should offer the proviso that, in making this general argument for moral restraint, I am speaking only of evident devils, or destructive technologies with no primary role in realms usually designated as human betterment: healing the sick, increasing agricultural yields, and so on. I am not talking about the more difficult, and common, problem of new technologies-cloning comes to mind as the current topic of greatest interest--with powerfully benevolent intended uses but also some pretty scary potential misuses in the wrong hands, or in the decent hands of people who have not pondered the unintended consequences of good deeds. Such technologies may be regulated, but surely should not be banned.)
Haldane's response to this obvious objection reflects all the arrogance described in the first part of this essay: I have superior scientific knowledge of this subject and can therefore be trusted to forecast future potentials and dangers; from what I know of chemistry, and from what I have learned from the data of World War I, chemical weapons will remain both effective and relatively humane and should therefore be further developed.
One of the grounds given for objection to
science is that science is responsible for such horrors as those of the late War. "You
scientific men (we are told) never think of the possible applications of your discoveries.
You do not mind whether they are used to
kill or to cure. Your method of thinking,
doubtless satisfactory when dealing with
molecules and atoms, renders you insensible
to the deference between right and wrong."
. . . The objection to scientific weapons
such as the gases of the late War, and such
new devices as may be employed in the
next, is essentially an objection to the
unknown. Fighting with lances or guns,
one can calculate, or thinks one can
calculate, one's chances. But with gas or
rays or microbes one has an altogether
different state of affairs. Poisonous gas had
a great moral effect, just because it was new
and incomprehensible. As long as we
permit ourselves to be afraid of the novel
and unknown, there will be a very great
temptation to use novel and unknown
weapons against us .... What 1
have said about mustard gas
might be applied, mutatis
mutandis, to most other
applications of science to human
life. They can all, I think, be
abused, but none perhaps is
always evil; and many, like
mustard gas, when we have got
over our first not very rational
objections to them, turn out to be,
on the whole, good.
In fact, Haldane didn't even grant moral arguments--or the imposition of moral restraints-any role at all in the prevention of war. He adopted the same parochial and arrogant position, still all too common among scientists, that war could be ended only by rational and scientific research: "War will be prevented only by a scientific study of its causes, such as has prevented most epidemic diseases."
I am no philosopher, and I do not wish to combat Haldane's argument on theoretical grounds here. Let us look instead at the basic empirical evidence, unwittingly presented by Haldane himself in Callinicus. And let me propose a test: If he is right, and scientific recommendations should be trusted because scientists can forecast the future in areas of their expertise, then the success of Haldane's own predictions will validate his approach.
I propose that two great impediments generally stand in the way of successful prediction: first, our inability, in principle, to know much about complex futures along the contingent and nondeterministic pathways of history; and second, the personal hubris that leads us to think we are acting in a purely and abstractly rational manner when our views are really motivated by unrecognized social and personal prejudices.
Callinicus contains an outstanding example of each error, and I rest my case for moral restraint here. Haldane does consider the argument that further development of chemical and biological weapons might prompt an investigation into even more powerful technologies of destruction-in particular, to unleashing the forces of the atom. But he dismisses this argument on scientific grounds of impossible achievement:
Of course, if we could utilize the forces
which we now know to exist inside the
atom, we should have such capacities for
destruction that I do not know of any
agency other than divine intervention which
would save humanity from complete and
peremptory annihilation .... [But] we
cannot utilize subatomic phenomena ....
We cannot make apparatus small enough to
disintegrate or fuse atomic nuclei .... We
can only bombard them with particles of
which perhaps one in a million hit, which
is like firing keys at a safe-door from a
machine gun a mile away in an attempt to
open it .... We know very little about the
structure of the atom and almost nothing
about how to modify it. And the prospect
of constructing such an apparatus seems to
me to be so remote that, when some
successor of mine is lecturing to a party
spending a holiday on the moon, it will
still be an unsolved (though not, I think,
an ultimately unsolvable) problem.
To which, we need only reply: Hiroshima, 1945; Mr. Armstrong on the Moon, 1969. And we are still here, in an admittedly precarious atomic world-thanks to moral and political restraint.
But the even greater danger of arrogant and "rational" predictions unwittingly based on unrecognized prejudice led Haldane to the silliest statement he ever made--one that might be deemed socially vicious if our laughter did not induce a more generous mood. Haldane tries to forecast the revised style of warfare that mustard gas must impose upon future conflicts. He claims that some people have a natural immunity, differently distributed among our racial groups. He holds that 20 percent of whites, but 80 percent of blacks, are unaffected by the gas. Haldane then constructs a truly dotty scenario for future gas warfare: vanguards of black troops will lead the attack; German forces, with less access to this aspect of human diversity, might be at a disadvantage, but their superior chemical knowledge should see them through, and balances should therefore be maintained:
It seems, then, that mustard gas would
enable an army to gain ground with jar less
killed on either side than the methods used
in the late War, and would tend to
establish a war of movement leading to a
fairly rapid decision, as in the campaigns of
the past. It would not upset the present
balance of power, Germany5 chemical
industry being counterposed by French
negro troops. Indians [that is, East Indians
available to British forces] may be expected
to be nearly as immune as negroes.
But now Haldane sees a hole in his argument. He steps back, breathes deeply, and finds a solution. Thank God for that 20 percent immunity among whites!
The American Army authorities made a
systematic examination of the susceptibility
of large numbers of recruits. They found
that there was a very resistant class,
comprising 20% of the white men tried,
but no less than 80% of the negroes. This
is intelligible, as the symptoms of mustard
gas blistering and sunburn are very similar,
and negroes are pretty well immune to
sunburn. It looks, therefore, as if, after a
slight preliminary test, it should be possible
to obtain colored troops who would all be
resistant to mustard gas blistering in
concentrations harmful to most white men.
Enough resistant whites are available to
I find it simply astonishing that this brilliant man, who preached the equality of humankind in numerous writings spanning more than fifty years, could be so caught in conventional racial prejudices and so wedded to the consequential and standard military practices of European and American armies that he couldn't expand his horizons far enough even to imagine the possibility of competent black officers and therefore had to sigh in relief at the availability of a few good men among the rarely resistant whites. If Haldane couldn't anticipate even this minor development in human relationships and potentialities, why should we trust his judgments about the far more problematical nature of future wars?
(This incident should carry the same message for current discussions about underrepresentation of minorities as managers of baseball teams or as quarterbacks in football. I also recall a famous and similar episode of ridiculously poor prediction in the history of biological determinism--the estimate by a major European car manufacturer, early in the century, that his business would be profitable but rather limited. European markets, he confidently predicted, would never demand more than a million automobiles--for only so many men in the lower classes had sufficient intellectual ability to work as chauffeurs! Don't you love the triply unacknowledged bias of this statement--that poor folks rarely rank high in fixed genetic intelligence and that neither women nor rich folks could ever be expected to drive a car?)
The logic of this argument must lead to a truly modest proposal. Wouldn't we all love to fix the world in one fell swoop of proactive genius? We must, of course, never stop dreaming and trying. But we must also temper our projects with a modesty born of understanding that we cannot predict the future and that the best-laid plans of mice and men often founder into an even deeper pit dug by unanticipated consequences. In this context, we should honor what might be called the "negative morality" of restraint and consideration, a principle that wise people have always understood (as embodied in the golden rule) and dreamers have generally rejected, sometimes for human good but more often for the evil that arises when demagogues and zealots try to impose their "true belief" upon all humanity, whatever the consequences.
The Hippocratic oath, often misunderstood as a great document about general moral principles in medicine, should be read as a manifesto for protecting the secret knowledge of a guild and for passing skills only to designated initiates. But the oath also includes a preeminent statement, later recast as a Latin motto for physicians, ranking (in my judgment) with the Socratic dictum "Know Thyself" as one of the two greatest tidbits of advice from antiquity. I can imagine no nobler rule of morality than this single phrase, which every human being should engrave into heart and mind: primum non nocere--above all, do no harm.
Stephen Jay Gould teaches biology, geology, and the history of science at Harvard University. He is also the Frederick P. Rose Honorary Curator in Invertebrates at the American Museum of Natural History.
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