From Thanksgiving on, Christmas builds like a signal fire. Red, green, and gold bulbs string between lampposts on city streets. Blue lights bloom exotically on evergreens in public parks.
Candles bank themselves like inverted V's in suburban windows.
Offices, selectively lighted, form ingenious cross patterns inside the elongated frames of skyscrapers.
Even the pools of yellow light from wreath-decked carbon lamps over superhighways become part of the blazing celebration.
And, of course, there are the lights on Christmas trees, ascending the fragrant pyramid by tiers to the star of Bethlehem on top.
''In spite of darkness it was day,'' the poet Richard Crashaw wrote of the first Christmas, and something like that conquest of darkness occurs every Christmas Eve. Villages, towns, and cities bring everything luminous that can blink, flash, or glare to a frenzied brilliance, more like the pyrotechnics of the Fourth of July.
Then, after Christmas, snap! - the lights shut off as abruptly as if an energy-hoarding homeowner had pulled a master switch. Discarded trees, stripped of lights and ornaments, are hauled to the dump. Colored bulbs and cords are packed away in corners of the attic. Yule logs, sending the sparks flying upward , are snuffed out as though on schedule.
By the new year, we have allowed the winter night to fall back into darkness. The morning and evening twilight are pierced only by the headlights of commuters , returned from their holidays, filing in slow caravans to and from work. The pedestrian, squeaking on new snow, looks into the January living room and sees now no candles, no tree - just the flicker of the television tube.
What an overnight change!
After we have lighted our way so gorgeously to the shopping malls and the pre-Christmas parties, why do we, with such haste, turn out the lights and declare the season closed?
Just when the light of lights, the real star of Bethlehem, could take over.
Just when Christmas, at last, might get to the point.
Instead, we hurry on to New Year's parties in basement apartments and busy ourselves with such undazzling activities as drawing up those year-end 10-best lists and making postholiday resolutions to diet.
Almost deliberately we dim down our lives.
We may fear the darkness. But we fear certain kinds of light even more, it seems. For light is a sort of knowledge. One becomes responsible for what one sees. What one sees can force one out of the comfortable darkness of familiar hillsides with friendly sheep. And who wants that?
No wonder we use Christmas lights as a distraction. And once Christmas is over, we run for the half-light that is our specialty the rest of the year - the world seen through sunglasses by day and TV by night.
But there are lights we cannot switch on and off like a toy stage set. ''The stars, with deep amaze,/Stand fixed in a steadfast gaze,'' Milton wrote, obsessed by these signals he himself could not see - convinced that all stars are, in a sense, stars of Bethlehem: the light of the world.
In the night sky, as another year draws to a close, the moon and the stars look down, giving off halos of radiance in the freezing air. If they are not the answer, they are, in all sorts of ways, the question.
They will be there next Christmas, and the Christmas after that, if we want to look up a little earlier, a little longer.
At Christmas, as at any other time, seeing the light is always a choice.