Marco PICCOLINO¹ and Nicholas J. WADE^2
1Dipartimento di Biologia, Università di Ferrara, Italy.  pic AT dns.unife.it
²Department of Psychology, University of Dundee, Dundee, Scotland.  n.j.wade AT dundee.ac.uk

Designs on flags and in other heraldic figures have not been accorded the recognition in the history of visual science that they warrant. We wish to draw attention to the ambiguity of the vase/face type evident in an Islamic flag hanging in the Chiesa dei Cavalieri di Santo Stefano in Pisa. In this flag, which dates at least from the mid-seventeenth century, the face components are displayed through a skilful use of decorative elements and the vase counterpart can be identified as a helmet or a dome of a mosque (both in an inverted position). The design on the flag represents one of the earliest examples of figure/ground ambiguity involving facing profiles. The ambiguity is surprising because the unknown artist has flown in the face of the Islamic prohibition on representing human figures in religious decorations; this would certainly have applied to flags of the Islamic army and navy. In addition, the overall image appearing inside the chequered border of the flag is highly suggestive of the forked sword, the dhû-l-fikar, the ‘perfect sword’ of divine origin and of religious symbolic value, an important emblem of Islam. It also bears some similarity with a geometrical instrument – the compass. There is likely to be a symbolic meaning in this resemblance of a sword with a compass because the latter was becoming an instrument of great military importance. At that time, battles were becoming less dependent on the individual courage of proud knights fighting with their swords and more on a series of geometrical calculations of which the military compass was an emblem. On the one hand, the visual (and material) ambiguity present in an instrument that could be both a geometrical and military tool is perhaps an illustration of the potential ambiguity present in any human progress. On the other hand, the beautiful, but neglected, examples of perceptual ambiguity evident in the Islamic flag might be taken to reflect a certain arrogance in visual science. Phenomena disclosed to the scientist’s eye are considered as discoveries. In many cases, those practitioners of vision, artists, have discovered and manipulated the same phenomena often centuries before they came under scientific scrutiny, and often with greater subtlety.

Pavia, Italy, 2006