I've read and heard many different theories, but most of them are silly or don't really tell you the background of this tradition. The only one that is not only interesting, but gives an explanation is the following: Northern people in Europe, highlanders or probably Vikings, used to knock their big mugs in a very vigorous manner and in groups (this means 5-15 people knocking all the mugs altogether) before or after battle to show their trustfulness. Why? Because if one of the drinks was poisoned, then knocking all the glasses in an energetical way, would cause liquid to slop over from one glass to the others, putting the poisoner in risk to get poisoned too. They used to share other things, like the bread, the water to get cleaned in the mornings, they all took pieces from the same cooked bird. I've read that people keep knocking glasses today, because they like the stimulating "chin-chin" noise of the glasses (according to psicologists), but this couldn't be the reason for our Northern friends, cause their beer mugs were made from wood mainly. So, at the end you can conclude that they used to do it for "safety" reasons. Cheers !!

I have heard another interesting story about knocking the glasses. It says that in order to enjoy your drink thoroughly you must feel it (or the glass?) with all your five senses. You can see it, taste it, touch and smell it. Unfortunately you can’t hear it. That’s why you knock the glasses to hear it.

A number of theories exist about clinking glasses with a toast. One theory, possibly stemming from that Greek habit, is that by clinking glasses, you could slosh the poison someone may have put into your wine back into theirs. Another theory is that the sound of clinking glasses was thought to drive the evil spirits out of the spirits, making it safe to drink. Clinking could also be a way to make contact since we no longer all drink from the same bowl. My favorite theory is that a good glass of wine or champagne appeals to the senses of sight, touch, taste and smell and, by clinking, it also appeals to the sense of sound, making it an all-encompassing sensual experience.

I don't buy the "poison may slop into the others glasses" hypothesis as a) that's what loving cups (as drinking vessels which are passed around are now called) are for and b) it's not reliable (as a loving cup is) as a safeguard and c) since when did poorly paid warriors both i) want to lose beer and ii) not trust their comrades with whom they've been fighting. (Not to mention that olden fighters used swords and brute strength, it was the shamans, druids, wizards & so on who dealt in poisons - and a fighter didn't drink with them (except maybe by way of a loving cup). There's also a lack of evidence for that anyway. Also: it has to be remembered that drinking from glassware was confined to the rich until the last couple of hundred years. (Depend how you define rich, I guess) It's more likely to stem from 2 factors: 1) It's an inclusion thing - let's all get drunk together. But rather than the cumbersome hand shaking (and when did that start? now there's a question!) let's touch tankards. (Though there's scant evidence) (There''s a theory that touching glasses/mugs indicates trust. But you trust your host if you drink with them, otherwise you don't drink - Loving Cups are ceremonial - no single host. Also, you don't clink your tea-cups or coffee mugs together. ) 2) The "Ching" you get from a clinked pair of glasses shows that they are of good quality. A crystal glass chings much better than moulded glass. A good quality glass chings better than a poor quality one and, more importantly, will survive the clinking better. It all points to a mere showing off (based upon an established practice) , a kind of adult game of conkers, whereby a host can show-off the quality of their glasses. And the greatest of all show-offs of material possessions were the Victorians. And that's probably where it stemmed from. You are being sociable, you being inclusive, and you are showing off. Comments welcome. I'm off for another drink. Chink-chink.

Friendship, celebration, good luck, and good times!! end

There are many stories behind this, however to what I have heard and agree is that it stimulates the sences. We have 5 sences as a human, TOUCH which is stimulated when you hold the glass for toasts. SMELL,which is stimulated by the smell of the drink.VISION, which is stimulated when u see the people and the glasses during toast.TASTE,which is stimulated when you will drink the alcohol. However the only sence that is not stimulated is the HEAR ie sound, so when you toast the glasses u hear the sound and stimulate the HEARING sence, this way all 5 sences are active during the toasts.