A few years ago, I had an epiphany about why we have Christmas. Or, more exactly, why Christmas is about light, and feasting, and presents, and goodwill to our fellow human beings. This isn't a religious explanation of Christmas, or an irreligious one. If anything, it's more like a sociological explanation, or maybe one influenced by evolutionary biology. Bear with me a bit; I've never really tried to put this into words before.
On Christmas Day a few years ago, I went for a walk after Christmas dinner to ward off incipient food coma. There was little or no snow, but it was cold enough to preserve a snowfall, and bleak, with the kind of white sky you sometimes see here in the northern states in the winter. The visible grass was yellow-brown, and the trees splayed their naked branches against the sky like black skeletons. The area in question is solidly suburban, but the houses are far enough apart that you get plenty of hints of what the land would be like if it hadn't mostly been cleared for building.
As I walked, I thought about what it would be like if I were suddenly thrown upon my own resources, with nothing but the clothes on my back, forced to find shelter and food. What a good thing it is, I thought, that I have family and friends, a warm house, and plenty to eat.
Then it occurred to me that Christmas celebrates family for just that reason.
Think about what it must have been like, say, in Northern Europe in the fifth century CE. Or the tenth, for that matter. Your heat was supplied by firewood. Your food was whatever game you could catch and kill and whatever grain or fruit you could store.
And if the winter was long enough, and hard enough, all of your preparations might not *be* enough. You would go hungry, and you might not live to see spring.
Add to that the depression brought on by very long nights and short days, the lack of light as well as warmth, and it's easy to see that people would huddle with family, rationing the scarce necessities as much as possible.
But that's not desirable either. Part of what makes a culture a culture, or a civilization a civilization, is its willingness to reach out and help the less fortunate. If that willingness to share is destroyed, chaos sets in, and the incentives to turn on one's neighbor to survive increase. As do the incentives to lie down and die in despair.
That's one of the reasons winter needs Christmas, or Yule, or some kind of holiday of light. Whether you think in terms of Santa bringing toys for the good children or the Wise Men bringing gifts to the child Jesus, you see the same message--help the stranger, it's good to do! The feasting and present giving are incentives to hang on to humanity when brutal conditions might well bring out the wolf that lurks in human nature. It also explains why Christmas doesn't seem to fit quite right in a warm, sunny climate--the physical pressures that shaped it into The Winter Holiday are lacking in places like Hawaii and New Zealand.
Christmas reminds us that, when things are bleakest, we need to look to each other for support. Because alone, the dark and cold may destroy us.