This category of sources, negatively defined as everything that is not a written source, can also be subdivided. First, there are objects: everything surviving from the past, from complete buildings to the smallest find. These objects need not be human-made, such
Figure 1 Roman road at the Welsh-English border (1st c. AD.) Roman surveyors and engineers have left their mark on the European landscape, in the form of roads, bridges, aqueducts, and field systems. On this aerial photograph, we can see the road known as Watling Street West, which runs south (the direction we are looking at) from Wroxeter, Roman Viroconium Cornoviorum, along the Welsh-English border. The road is still in use, and with its hedgerows is easily the most conspicuous feature of this landscape. It runs between the hills and marshland, along the valley floor. In the far distance, it bends toward the so-called Church Stretton Gap. The road may have been built as part of the Roman effort to subdue Wales between 43 and 77. Photo: Cambridge University Collection of Aerial Photography
As tools, jewelry, or coins. Also, biological matter, from a complete skeleton down to carbonized seeds or fossilized pollen, should be included. Architectural features are the most obvious immovable objects, but many other immovable objects or even particular characteristics of such objects can be relevant, from a discolored patch of soil or a crop mark as indicative of some past occurrence, to complete landscapes or infrastructures. These sources are all the subject of archaeology, assisted by a range of scientific disciplines such as air photography, cartography, and even surveying by satellite.
Second, there are images made by humans, of course objects too, but still easily distinguished as falling in a category of their own. Images or representations are unwritten sources, but are more closely related to texts than are other objects. Texts are also, in a sense, images made by humans of their surroundings, their fellow creatures, or themselves. Images should be approached with care: never can they be used as if they convey the same kind of verity that we find in documentary photography. Works of imagination would actually be a better word to describe many of the images that have come down to us. In order to interpret the images produced during some past period, one has to have some acquaintance with the procedures governing portrayal during that period. Even if we have such knowledge of a period’s image making, many questions surrounding the use of images as sources will remain unanswered.
Generally speaking, unwritten sources will never be allowed to monopolize research, unless there is no alternative (obviously, this is the case when dealing with a community that is without writing; also, there are scripts that as yet have not been deciphered). However, unwritten evidence can complete, nuance, or correct the views based on the written sources. In that way, unwritten sources are without doubt of the utmost importance. However, interpreting, for example, the remains of a wall is not always an easy task, and interpreting the image painted on a wall or a pot might very well be much more difficult still. The written sources, primary or secondary, will always be fundamental to any historical account.