Touch Wood?

From:  "red"

Why is it people say "touch wood" when they don't want something to happen (after mentioning it) even if they claim not to be superstitious. What does it mean?

Ok well personally I always thought it was "Knock on Wood" but we'll see what kind of answer either way we can come up with. *Lauren*

TB faithfully answered this: 

In America it is generally known as "knock on wood". In England is is known as "touch wood". The expression goes back to pre christian times, possibly druid in origin. It is meant to ward off or absorb "evil" for people who are superstitious. Trees shelter, shade, provide wood for fuel, heat and shelter. In ancient times they were the tallest object around so they were hit most often by lightning warding off lightning's evil from people and their homes.

Bjave Storm responded with this: 

Cool. Hey, on the knock on wood question- it is my understanding that in the days of olde, when traveling on ships... you always wanted to knock on wood because wood floats... so it's a good thing to have close by... pretty cool huh? Say, have to run... because a stich in time saves nine. :)

Aalandra did her research on the situation: 

"To touch wood is a superstition action to ward off any evil consequences, say of untimely boasting; it can also be a charm to bring good luck. There is, I’m told, an old Irish belief that you should knock on wood to let the little people know that you are thanking them for a bit of good luck. Others have sought a meaning in which the wood symbolises the timber of the cross, but this may be a Christianisation of an older ritual. The phrase itself seems to be modern, as the oldest citation for touch wood in the Oxford English Dictionary dates only from 1908; my searches haven’t turned up anything earlier. "

David K gave us his views on the situation: 

First of all, I believe the British say "touch wood" while Americans say "knock on wood". And I also believe that it stems from an old pagan religious belief that trees were worshipped because they harbor protective spirits. If you touch the wood of the tree, you are also protected from the evil spirits.

Stephen H. rattled of this answer: 

Nock on wood huh? Well, like a suprising number of quirky traditions this one has roots with old Celtic and Druid belief. Waaaay back when people believed in all sorts of bad spirits and that said spirits could inhabit anything. Wood was thought to be especially favored among these bad spirits. To drive them out you simply knocked them out. Nock on wood, bad spirit leaves. You have good wood, you have good luck.

Trace summed it up with this: 

To touch wood is a superstition action to ward off any evil consequences, say of untimely boasting; it can also be a charm to bring good luck. The origin is quite unknown, though some writers have pointed to pre-Christian rituals involving the spirits of sacred trees such as the oak, ash, holly or hawthorn. There is, I’m told, an old Irish belief that you should knock on wood to let the little people know that you are thanking them for a bit of good luck. Others have sought a meaning in which the wood symbolises the timber of the cross, but this may be a Christianisation of an older ritual. The phrase itself seems to be modern, as the oldest citation for touch wood in the Oxford English Dictionary dates only from 1908; my searches haven’t turned up anything earlier. (Incidentally, that work doesn’t have a single example of knock on wood, which is the American version of the British touch wood.)