Much of what we now accept as 'part of Halloween' appears to have evolved from Ireland and from there spread to North America as many Irish people left their homeland for the New World. Its deepest roots are undoubtedly pre-Christian and are based upon the rituals associated with the changes of the season. Mid-winter, mid-summer, the coming of spring and the end of the harvest were all recognised and celebrated from earliest times.
With the coming of Christianity the old festivals took on a Christian element. So Christmas was celebrated in mid-winter, Easter at springtide and so on. This accounts for mid-winter symbols, such as yule logs, holly and ivy and robins, being associated with Christmas, and fertility symbols - eggs, rabbits - getting attached to Easter. We shouldn't be surprised by this; Christianity, with its origins in warmer climes, lays down no rules for how such things as the winter solstice should be marked. So people just got on and did what they'd always done at that time of year.
But back to Halloween. "Hallow" is just an old word for "saint", so All Hallows' E'en (or eve) just means the evening before All Saints' Day, similar to Christmas Eve And New Year's Eve being the day before their respective holidays. But tagged on to this Christian idea is the old Celtic fire festival - "Samhain" - with its bonfires, ghosts, evil spirits and jack'o'lanterns.
In Somerset they also had "Punky Night" where, on the.last Thursday in October (tonight), children went from door to door begging for candles for their jack'o'lanterns and threatened householders with the following rhyme:
"Give me a candle, give me a light. If you don't, you'll get a fright"
which sounds a lot like "trick or treat" to me.
In reading what I could find out about Halloween I came across a common misconception: the idea that the people who believed in pagan myths and customs were doing so out of some mystical belief in the past which defied all notions of common sense and learning. This was not really the case; they were just making sense of the world in the best way they could at that time. We may know the scientific reason for the lengthening and shortening of the days, for the growth of plants and the coming of floods, drought or famine, but they did not and were not aware of the ancient origins of their beliefs.
In much the same way, when we do a mathematical calculation, we are not aware that we are following the beliefs of Arab mathematicians of centuries past; we are just doing what we are sure is correct. If subsequent generations discover that 2+2=5 then they will regard us as foolish numbskulls who blindly folllowed the word of ancient mystics in the light of what they regard as common sense. For us, 2+2=4 and we can't see any other argument. And those people from the past couldn't see any other argument either.
And another thing....
If the idea that these age-old customs are constantly undergoing change is a strange concept, then consider this: Next week I shall be organising a "Halloween Disco" for the pupils at school. Here we shall see Harry Potter-inspired wizards dancing to "Ghostbusters" by Ray Parker Jr and Michael Jackson's "Thriller". What would the Ancient Celts make of that?????
Take care (especially if the Punkies are about).