Most definitions of civilization that I've seen have three requirements: living in houses, metal technology, and a written language. Before these three we have pre-history; oral tradition and what can be reconstructed through the use of artifacts. After these three we have history as we have sources of information. Recently while reading a book about Babylon I was struck by the fact that of the five thousand years of history we have twenty-five hundred of them cover the Sumerians and their successors. Half of all history is Sumerian.
Santayana's dictum always seemed to me to be an intellectually lazy was to advance one's own argument. Maybe not. Over the past five thousand years our way of life and understanding has changed; however, our behavior and human nature hasn't. It's certainly reasonable to expect that the structure of human events would repeat over such a long time, much the same as there are no new plots for stories. What changes are magnitudes and details. Better than Santayana is Mark Twain's observation: If history doesn't repeat, it at least rhymes.
