Wine is not a necessity of any people's diet, yet it has colonized the greater part of those climatic zones which are congenial to it, and it has done so, very often to the detriment of the people's essential food supplies. There have been three principle forces for this, spleen, religion, and profit.

First, the human condition being what it is, only a very small number of very primitive tribes have failed to develop some intoxicant to help man face the facts of life. Poppy juice, toxic fungi, the dried flowers of a coccus, the leaves of coco bush, but neither of them can compare in economic and social importance with alcohol. And the wine of the grape has long been the least concerning medium in which alcohol can be taken and the least liable to dangerous abuse.

Secondly, the strange power of intoxicants to release the human spirit from the control of mind led to their being regarded with superstitious awe. Their use became a religious rite and this was the case of wine, as of others. In the sixth century B.C., Orphism gave a new, long and civilized lease of power to the formerly savage and barbarous religion of Dionysus; the use of wine in the rites entered into the later religious of the Mediterranean peoples; and Christianity, by the encharistic use of wine, borrowed from elder cults, carried the religious significance of wine-drinking forward into the two Christian civilizations, the Greek and the Latin. The massive conservation of these two branches of Christianity accomplished what no other social force could have done--maintained the religious attribute of an intoxicant into a sophisticated technological epoch.

Thirdly, the cash yield per acre-man-hour of viticulture has nearly always been from three to ten times as great as that from any other kind of fanning or gardening. However, in fact, two forces working against the vine, one natural, the other social, have limited the spread of vineyards even further.