• Lorraine Daston &
  • Peter Galison
Zone Books, MIT Press: 2007. 500 pp. £25.95, $38.95 1890951781 9781890951788 | ISBN: 1-890-95178-1

All scientists think they know what objectivity is. But objectivity has a history full of fascinating changes of sense, and now bears several different meanings. Most involve an absence: of distortion; of human bias or subjectivity; or of the particularities of location and culture. It is one of the more austere virtues, often seen as a stern judge that disallows ornamentation.

In their book Objectivity, Lorraine Daston and Peter Galison pursue the idea that we can best explore the many meanings of objectivity through an examination of images — their book is essentially about the ideal of objectivity as applied to scientific atlases, or reference books of illustrations. In such works, objectivity is largely about restrictions on the composition and presentation of scientific images. Objectivity, however, offers a cornucopia of images ranging from plants and birds to embryos and snowflakes, and it is enriched by the authors' expert sleuthing and wide intellectual reach.

Credit: A. MARTIN

The heart of objectivity, for Daston and Galison, is 'mechanical objectivity', which had its heyday from about 1850 to 1920. The phrase implies that scientists proceeded methodically, using automation whenever possible, to reduce human intervention to a minimum. This era of impersonal objectivity was preceded, the authors propose, by one of 'truth to nature' and succeeded by one of 'trained judgement'.

Using such names for historical periods may seem incendiary, first by implying that objectivity has had its day, and further by placing it in opposition to both truth and expert judgement. But the authors have very particular meanings in mind. The terminology is confusing, though, because scientists rarely used the word 'objectivity' until some decades into the era that Daston and Galison name for it.

Objectivity here is more about morality than validity. Mechanical objectivity made suppression of self a duty, a triumph of abstemious will over the prideful claim of competence to judge and interpret. The contrast between mechanical objectivity and devotion to truth is subtle but important. A uniformly sharp photograph might well be confusing, masking the main point in irrelevant detail. It is easier to identify a flower or recognize a diseased kidney from an idealized drawing than from an unretouched photograph.

Daston and Galison define the era of mechanical objectivity by a profound reluctance of scientists seeking to illustrate their work to stray from the rigorous accuracy of the camera. Yet photographic accuracy, at least until 1890, was far from rigorous. Choices had to be made in preparing materials, composing, illuminating and framing the picture, and sometimes retouching an image, and the technology of photographic reproduction in the 1880s involved intense human labour. The language of objectivity, then, did not so much distinguish photography from drawing as mark off certain ways of preparing photographs from others. An 'objective' image was one that minimized the effects of human intervention.

In contrast, naturalists of Daston and Galison's earlier 'truth-to-nature' era felt no such compunctions. They used illustrations to get at something more fundamental than the individual: an underlying type. This is 'truth' in a very special sense. The eighteenth-century naturalists Carl Linnaeus and René Réaumur supervised their artists meticulously, not to ensure that they drew a specimen accurately, but to make sure that they departed from its particularity where this could reveal a deeper level of truth.

The authors argue that science and art diverged around 1850, with science insisting on objectivity in its ascetic form, and art rejecting the mere reproduction of what can be seen in the world. They propose that different forms of objectivity arose in conjunction with new understandings of the 'scientific self', which by 1850 had become quite different from the artist. This focus on the changing character of the scientist offers important insights, but the authors overstate their case for the rupture between science and art. The very phrase 'truth to nature' is associated specifically with the pre-Raphaelites, a mid-nineteenth-century artistic movement grounded in an admiration for the writer and aesthete John Ruskin (indeed Tate Britain had a major exhibition in 2004 called “Pre-Raphaelite Vision: Truth to Nature”). Ruskin, whom Daston and Galison fail to mention, was as committed to the union of scientific and artistic perspectives as the poet-naturalist Johann Wolfgang von Goethe, who features prominently.

How could objectivity interfere with truth? Daston and Galison introduce this notion at the outset with the story of the British physicist Arthur Worthington. In 1875, Worthington began chronicling the beautiful symmetries of fluid motion revealed by a droplet of mercury hitting a clear glass plate. In 1894 he finally captured the splash in a photograph. To his dismay, it was a mess, with none of the perfection he thought he had witnessed. Did the mechanical image occasion a sacrifice of truth? Yes, if 'truth' refers to such elegant forms as admired by Goethe a century earlier. In a more prosaic sense, Worthington had finally got it right. He concluded, sadly, that the symmetries he thought he saw were artefacts of his own flawed vision.

The authors draw back from claiming in a strict sense that objectivity was invented, had its day in the sun, and then passed away. Yet something like this, much qualified, is the organizing principle of the book. This is problematic, not least because the argument is based on the special case of scientific atlases and then extended to all of science. Can Daston and Galison really claim that trained judgement never existed as a conscious alternative to unthinking routines of objectivity until about 1920? They are, however, persuasive in arguing that a vast expansion of scientific education in the early twentieth century helped to make expert judgement more acceptable to science.

By this time, scientists and other professionals were arguing with increasing conviction that mechanical procedures could not really get at what is most interesting. The interpretation of images, they said, depended on a capacity to see 'family resemblance', which scientists, with the aid of well-drawn images, could learn to recognize reliably. Daston and Galison demonstrate, with wonderful insight, that this notion of family resemblance was simultaneously scientific, philosophical and pictorial. Ludwig Wittgenstein, in enunciating it, referred back to some striking composite photographs through which the statistician and eugenicist Francis Galton tried to establish racial and social types. Scientists of this period repeatedly likened the analysis of an image in physics or medicine to detecting racial background from a photograph.

The book concludes with an analysis of images from today, perhaps a fourth epoch in the history of objectivity. Modern techniques of image production at the nanoscale use processes that record themselves (Daston and Galison call these 'presentations' rather than 'representations'). These attest to the extraordinary merging, in certain areas, of technology with science, and sometimes also with marketing. The commercialization of science presents its own problems, for scientific objectivity is about more than communication among scientists. As important today are the views of political leaders and the public. Modern scientists, enmeshed in elaborate systems of recruitment, training and communication, may have less need of mechanical objectivity than their nineteenth-century counterparts, but they find it difficult to speak to the public with the same kind of assurance. Critics of the science establishment have turned the rhetoric of (mindless) mechanical objectivity against science, objecting to the sensible but unrigorous application of experience and understanding on which good science depends. Scientists need more than ever before to gain, and to deserve, public respect for their skilled work and uncorrupted expert judgement.