It’s time to take action on the passive voice, says Philip Ball

The strange thing about Albert Einstein’s classic 1905 papers on relativity, quantum theory and Brownian motion is that he is largely absent from them. That’s to say, he hardly ever uses the first person singular to put himself in the reference frame. We and Einstein do it all together: ‘We have now derived…’, ‘We now imagine space to be…’ He pops up a little thrillingly at the start of the extraordinarily brief E=mc2’ paper, but quickly vanishes beneath the passive voice and the impersonal ‘one concludes’. It wasn’t his intention but this all makes Einstein sound magisterial. 

Hard reign

I’m left thinking about this use of voice after reading a paper by ‘science studies’ researchers Daniele Fanelli of the University of Edinburgh, UK, and Wolfgang Glänzel of the Catholic University of Leuven, Belgium.1 They report a bibliometric analysis of around 29,000 papers covering all the sciences from maths and physics to social sciences, as well as some in the humanities, showing significant differences in style and content. Differences that, they say, point to a genuine hierarchy of sciences, along the lines first postulated by the French philosopher Auguste Comte in the 1830s. That’s to say, physics and maths are the ‘hardest’ sciences, and they become progressively ‘softer’ as we move through chemistry, the life sciences and the social sciences. The key criterion the authors use for this classification is the degree of consensus in the field, as revealed for example by the number, age and overlap of references.

If scientists care about precise reporting, they should insist on planting themselves in their papers

There’s a lot to discuss in these interesting findings, but one aspect that caught my attention was a proposal that use of personal pronouns could be a measure of ‘hardness’. ‘Scientists aim at making universal claims, and their style of writing tends to be as impersonal as possible,’ say Fanelli and Glänzel. ‘In the humanities, on the other hand, the emphasis tends to be on originality, individuality and argumentation, which makes the use of first person more common.’ They found that indeed the ‘harder’ sciences tend to use personal pronouns less often.

The assumption here is that an impersonal, passive voice suggests a universal truth, which of course it does. But that’s the whole point: scientists actively cultivated the impersonal tone as a rhetorical device to persuade and to convey authority. Fanelli and Glänzel’s implication that the passive voice reflects science’s ability to deliver absolute knowledge is a case of science falling for its own tricks. 

The process began with the institutionalisation of science in the 17th century, and it was a feature of what historian Steven Shapin has called the ‘literary technology’ of that age: a style of writing intended to sound convincing. In writing Elements of chemistry, Antoine Lavoisier calculatedly shifts from ‘I’ to ‘we’: he is personally present when distinguishing his own discoveries from those of Joseph Priestley and Carl Scheele, but tells us bossily that ‘we shall presently see what we ought to think’ when ‘we’ choose between them.

There were some good reasons for this impersonal style. Experimental scientists wanted to free themselves from the claims of the Renaissance magi to have received deep insights through personal revelation; on the contrary, scientists found stuff out using procedures that anyone (with sufficient care and education) could conduct. So it didn’t matter who you were anymore – an attitude encapsulated in Claude Bernard’s remark in 1865 that ‘Art is I; Science is We.’ Or better still, science is ‘It is shown that…’

We are scientists

Yet the pendulum is swinging. Many books on writing scientific papers tend now to recommend the active voice. For example, in Successful scientific writing, Janice Matthews and Robert Matthews say ‘Many scientists overuse the passive voice. They seem to feel that every sentence must be written in passive terms, and they undergo elaborate contortions to do so.’ But the passive voice, the authors say, ‘often obscures your true meaning and compounds your chances of producing pompous prose’. The American Institute of Physics, American Chemical Society and American Medical Association all recommend the active voice and use of pronouns, although they accept the passive voice for methods sections.

I would go further. If scientists care about precise reporting, they should insist on planting themselves in their papers. Their fallibility, preconceptions and opinions are a part of the picture, and it’s misleading to imply otherwise. For many of the scientists who, during my years as an editor at Nature, balked at writing ‘I’ rather than ‘We’ in their single-author papers, the worry was not that they’d seem less authoritative but rather, too arrogant. Yet I suspect ‘I’ also seemed uncomfortably exposing. Either way, if you did the work, you’ve got to admit to it.