How can we hope to understand societies that existed long ago? Is what we think we understand about them merely the reflection of our own ideas and preoccupations? The problems are particularly severe versions of the general difficulty, much discussed by philosophers and anthropologists in the 1950s and 1960s, of understanding alien cultures. Today's field anthropologist can at least cross-question the people he or she is studying, to check whether his or her interpretation of their ideas and behaviour is along the right lines, and at least sometimes they will confirm that it is, though whether that is simply out of politeness or deference remains an open question. For the student of ancient societies, by contrast, most of the evidence has long been in. Occasionally a new Greek papyrus is found in the sands of Egypt or wrapped around a mummy: far more often silk scrolls or bamboo slips come to light in Chinese tombs. But the point holds as a generalization, and besides, we certainly cannot question any of our ancient subjects. I shall be returning to the problems of the bias and lacunae in our sources at the end of this chapter.
While the problems of the range of evidence are serious, those of the conceptual framework within which interpretation can proceed are even more so. The difficulty can be put in the form of a dilemma. On the one hand are the risks of distortion if we use the conceptual tools familiar to us. In the case of the history of science, especially, that has led to both anachronism and teleology. To talk of the ancients' chemical theories, for instance, is bound to distort what they were doing, since chemistry as we know it today is a product of the eighteenth and nineteenth centuries: I shall be dealing with the problem of talk about science as such in the ancient world in the next chapter. But teleology is even more pernicious, in that it assumes that the ancients aimed to approximate to modern ideas—and as they did not get there, they must have failed miserably. But of course they could not see into the future.