Renfrew desires to lay out the course the various disciplines related to and under the name archaeology will take in the future. First, he relates the history of archaeology itself with a brief (yet repetitive) overview of the science and the various changes it has gone through. While he is doing this, the reader actually gets to learn a great deal, specifically how the scientists have come to view pre-history: not as a savage past leading up to modern civilization, but as a place where humans (and others) had their own lives and values.
To get into those minds is the task for archaeologists now, is the most basic summation of the rest of the book.