A shadow

Typically, it is impossible to have an index (the mark) and its referent (the thing that makes the mark) both fully visible. The fnger must move away before the fngerprint can be seen. But it becomes possible when we consider the phenomenon of a shadow. In a shadow, both the thing and its indexical trace can be in the same place at the same time. In fact, the index is necessarily coincident with its referent - if the event that caused the trace was no longer present, the trace would cease to exist.

This special kind of index gives us, as Barthes terms it ‘a perception of the having-been-there of an object’.22 It also gives us a perception (or an awareness) of the being-there now. The existence of the indexical image is dependent on the enduring presence of its referent, and it is in this temporal dependence that the shadow becomes an index of the now.

Like the shadow, the refected image - such as that on a dark window, mirror or other shiny specular surface - is dependent on the live presence of the object being refected. It is also dependent on the position of the viewer. The shadow image does not move if I circle around it (it only moves if the light source or referent does) but if I step a metre to the left or right when infront of a refected image, the content of that image changes. In this way, the presence of the subject viewing the refection (as well as the presence of the object being refected) is drawn into to the surface of the indexical image. In gazing at a refection, I am not only aware that this image represents what-is-therein-the-world-now, but also that this now-is-alsowhere-I-am.

Unlike a photograph which is eternally frozen at an undefned location in the past, the refected image is in a perpetual state of live-ness. As such a refection is a unique order of index. With the power to give us a sense of the being-there (of the object), the having been-there (to make its trace) and the beinghere-now-with-me (through its live-ness). Pierce alluded to the special power of immediacy in his discussion of the photograph - singling out the ‘instantaneous’ photograph as having particular power as an indexical sign.

Photographs, Peirce says, 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. In that aspect, then, they belong to a second class of signs [indices], those by physical connection.22

This instructive power is even further heightened in the case of the refection. A refection is not just an instantaneous image, it remains perpetually so. That is to say it is always temporally active- it is not a still image made in the past (even if that past was only an instant ago) but a live image of now. It is perpetually making a new image at every given moment.

This liveness means that, on encountering a refected image, we don’t just know that the image is exactly like the objects it represents but we also know that we are in the same exact world alongside them both.