Signification and Sensibility: Notes on the Photographic Index

Is smoke a representation of the fire that produces it? Do shadows represent the things that cast them. Do the rings of a tree represent its age? Is the inverted view seen in a dewdrop a representation? Is a footprint? Or an echo?

For Charles Sanders Peirce (1839 – 1914) each of the above would constitute what he defined as “Indices.” For Peirce "An Index [singular] is a sign which refers to the Object that it denotes by virtue of being really affected by that Object.” Indices “represent their objects independently of any resemblance to them, only by virtue of real connections with them.”

This notion of a causal connection between the index and its object has often been thought to confer a special status upon indexical signs, and amongst such signs none has figured more prominently, or generated more discussion, than that of the photograph. Photographs are the result of electrochemical changes manifested in a photosensitive surface in response to exposure to light, and this causal relationship is believed to contribute to, or constitute even, the unique - and some would say “objective” – identity or “truth” of photographic images.

Perhaps most notable of all commentators upon the indexical nature of photography has been the French literary theorist and philosopher Roland Barthes whose 1964 Essay “The Rhetoric of the Image” proclaimed that the photograph is a “message without a code.” (other theorists argue something similar when they claim that photography is “transparent” to its subject) For Barthes this unique feature of photography is a consequence of its “absolutely analogical nature.” Barthes argued that photography should thus be differentiated from “drawing which, even when denoted, is a coded message.”

Since 1964 many theorists have followed in Barthes’ footsteps, variously arguing for the unique status of photography, its “truth claims”, its essential “objectivity”, “immediacy” or “reality.” But rather than explore the intricacies of these theories I’d like instead to make a point that may well have been obvious right from the outset.

The smoke rising from a chimney is not a representation and nor is a shadow, an echo or the miniature view spied in a dewdrop. It is true that these things have direct causes but the fact that these are implied, suggested, connoted, denoted, indicated, signified or otherwise made evident does not bring about a transformation of their subsequent effects into representations. An obvious or inevitable connection between an effect and its cause does not yield a representation. Representations are the products of intentional acts of substitution.

And what then of the unique status of photography? Certainly it can’t be anything to do with its absolute analogical nature. And if it is, we are simply left with the very obvious question raised by digital photography. It might then be argued that the analogical nature of photography, to which Barthes was referring, was in fact closer to what C. S. Peirce meant when he wrote:

“Photographs, especially instantaneous photographs, are very instructive, because we know that they are in certain respects exactly like the objects they represent. But this resemblance is due to the photographs having been produced under such circumstances that they were physically forced to correspond point by point to nature.”

Notice though that Peirce states that photographs “are in certain respects exactly like the objects they represent.” Did he mean to say that they are exactly the same as the objects they represent? Presumably not. To be exactly like is precisely not to be exactly the same. If Peirce had been more exacting he should perhaps have written: photographs are in certain respects and in certain circumstances perceptually indiscriminable from the things they represent. In other words, if the circumstances of presentation are very tightly controlled (in a lab experiment for example), we can find that we are unable to discriminate the difference between a photograph and whatever it represents in a variety of respects. It is nonetheless likely that we could easily distinguish between the representation and its object but it is important to point out here that conceptual distinguishability and perceptual discriminability are distinctly different. We are capable of distinguishing between things as a consequence of our ability to use language, whereas our capacity to discriminate perceptually is genetically acquired. Infants don’t have to learn to see photographic representations any more than they have to learn to see. Distinguishing, on the other hand, requires the development conceptual understanding.

It should be apparent then, that our genetically acquired ability to perceptually discriminate or, more precisely, to fail to discriminate, is the decisive factor that enables photographic representation. And it should also be noted that this includes all photorealistic depictions, despite Barthes’ logically unsupportable contention that all drawings are coded.

It turns out then, that Peirce’s theory of the index – at least as it pertains to photographs – is incapable of throwing much light upon the nature of  photography. It both lacks analytical precision and places too great an emphasis on the immediate causal history of photographs. As every digital photograph clearly attests, the causal history – even the immediate causal history - of the photographic image is often little more than a mystery to most of us. The same can be said of analogue photography in fact. This isn’t to say that the causal history of photographs is unimportant. Of course, some makers of photographic images deliberately choose to emphasise the indexical aspects of their craft; to draw attention to the processes of production, to the methods, qualities and materiality of the print and so on. In this sense they rely on, or seek to encourage, our abilities to make distinctions, to recognise, to compare and to distinguish. We might also say that these often subtle qualities draw upon our sensibilities, but this word demands a little care. If by sensibilities we mean some kind of genetically inherited ability to sense the finer details and qualities of things then we might have reason to be sceptical. Are our sensibilities genetically acquired? To some small degree perhaps they are, but for the most part our sensibilities are developed and refined through experience and most especially through considered attention, assisted significantly by our abilities to use language. Sensibilities are cultivated.

It might also be argued that photographs function by way of reference, signification or meaning. There is no doubt at all that photographs indicate, connote, denote, signify and allude to all kinds of things but they are by no means reliant upon these forms of signification because meaning, like sensibility, derives from our skills as language users. Although photography and other forms of non-verbal representation are enormously influenced, assisted and informed by language – by our abilities to distinguish - they are made possible by circumstances that must certainly have preceded our capacity to use language. They are derived moreover from a felicitous vulnerability in our perceptual capacities, a systematic perceptual weakness that we have discovered how to exploit to our profound and extraordinary advantage.