Mirrors, like camera lenses, reconstitute a chosen subject onto a flat surface by redirecting beams of light. How could they fail to fascinate a photographer like Duane Michals, who has spent his life mistrusting the world of appearances in order to delve into truths that lie beyond the surface, but who must do so - because of the very nature of his medium - on just such a surface?.

Unusually for a photographer, Michals has repeatedly stressed his suspicion of the purely visual to the extent even of abandoning, from time to time, the lens-based image in favour of purely verbal description. Having introduced handwritten inscriptions onto his prints in the late 1960s, in the mid-1970s he made a series of works combining texts and images and some consisting of text alone. All of these were written onto photographic paper and editioned in the same way as the pictures taken with a camera, laboriously copied out for each separately signed and numbered print, as a way of asserting that even in these purely calligraphic works he continued to identify himself as a photographer, albeit one of a very particular sort.

One of the most important of these text-only pieces, amounting almost to a statement of belief, is A Failed Attempt to Photograph Reality (1975), which consists of just four sentences in which he summarizes with wonderful economy his understanding that any attempt to photograph 'reality' can only end in failure because it is based on a confusion between experience and the transient look of things. His conclusion: "I am a reflection photographing other reflections within a reflection" suggests a profound unease with the whole process of trying to trap appearance, a futile process which for him results in an uncertainty about his very own existence.

Another text-led work of that period, Someone Left a Message for You (1974), presents the artist's written message entirely within a sequence of four photographic images. The viewer is presented with the photographic reproduction of a piece of paper onto which a left-handed person appears to be writing a sentence backwards in mirror-writing. As used by Leonardo da Vinci on some of his annotated manuscripts, it is a technique associated with secret knowledge and private erudition. For Michals, however, the reversed handwriting, which can easily be deciphered by placing a mirror up to the surface, functions as a means of drawing the spectator into the creative act as a form of communication between the imagination of the artist and that of the intended audience. "As you read this" says the message, "I am entering your mind". In the very act of hearing oneself say these words, the process has been made complete. And it has been achieved through one of the simplest devices available to a photographer: that of flipping the negative before printing. (…)