Our memory is like that burning scrap of paper. We use it to light up the past. First of all our own, and then we ask old people to tell us what they… - Ernst Gombrich

Whether we know it or not, we always approach the past with some preconceived ideas, with a rudimentary theory we wish to test. In this as in many other respects the cultural historian does not differ all that much from his predecessor, the traveller to foreign lands. Not the professional traveller who is only interested in one particular errand, be it the exploration of a country’s kinship system or its hydroelectric schemes, but the broad-minded traveller who wants to understand the culture of the country in which he finds himself.

We are all inclined to accept conventional forms or colours as the only correct ones. Children sometimes think that stars must be star-shaped, though naturally they are not. The people who insist that in a picture the sky must be blue, and the grass green, are not very different from these children. They get indignant if they see other colours in a picture, but if we try to forget all we have heard about green grass and blue skies, and look at the world as if we had just arrived from another planet on a voyage of discovery and were seeing it for the first time, we may find that things are apt to have the most surprising colours.

Anyone who can handle a needle convincingly can make us see a thread which is not there.