[5] It is difficult to find words which have a sequence or gradation of meaning with respect to both development and a range of time in the past, or with a range of time from somewhere in the past which is perhaps not yet ended. One standard Webster definition of _stage_ is: “One of the steps into which the material development of man ... is divided.” I cannot find any dictionary definition that suggests which of the words, _stage_ or _era_, has the meaning of a longer span of time. Therefore, I have chosen to let my eras be shorter, and to subdivide my stages into eras. Webster gives _era_ as: “A signal stage of history, an epoch.” When I want to subdivide my eras, I find myself using _sub-eras_. Thus I speak of the _eras_ within a _stage_ and of the _sub-eras_ within an _era_; that is, I do so when I feel that I really have to, and when the evidence is clear enough to allow it. The food-producing revolution ushers in the _food-producing stage_. This stage began to be replaced by the _industrial stage_ only about two hundred years ago. Now notice that my stage divisions are in terms of technology and economics. We must think sharply to be sure that the subdivisions of the stages, the eras, are in the same terms. This does not mean that I think technology and economics are the only important realms of culture. It is rather that for most of prehistoric time the materials left to the archeologists tend to limit our deductions to technology and economics. I’m so soon out of my competence, as conventional ancient history begins, that I shall only suggest the earlier eras of the food-producing stage to you. This book is about prehistory, and I’m not a universal historian. THE TWO EARLIEST ERAS OF THE FOOD-PRODUCING STAGE The food-producing stage seems to appear in western Asia with really revolutionary suddenness. It is seen by the relative speed with which the traces of new crafts appear in the earliest village-farming community sites we’ve dug. It is seen by the spread and multiplication of these sites themselves, and the remarkable growth in human population we deduce from this increase in sites. We’ll look at some of these sites and the archeological traces they yield in the next chapter. When such village sites begin to appear, I believe we are in the _era of the primary village-farming community_. I also believe this is the second era of the food-producing stage. The first era of the food-producing stage, I believe, was an _era of incipient cultivation and animal domestication_. I keep saying “I believe” because the actual evidence for this earlier era is so slight that one has to set it up mainly by playing a hunch for it. The reason for playing the hunch goes about as follows.