God bless you

Bless you is a common English expression used to wish a person well after sneezing.

Origins

There are many theories regarding the origin of this custom. One well known and strongly believed theory is that it began as a blessing near the start of the Plague of Justinian or one of the more minor plagues which followed with the words of Pope Gregory the Great. Crowds took to the streets praying to God and when a person sneezed they were immediately blessed God bless you! for fear that they may be developing symptoms of the plague.

Superstition

Many of the other theories are based on superstitions and urban legends about sneezing and what a sneeze entails. Some well known superstitions that may have brought the phrase bless you into common use are:

• The heart stops when you sneeze (it doesn't), and the phrase bless you was meant to ensure the return of life or to encourage your heart to continue beating.
• A sneeze is the expulsion of some sort of evil, and the phrase was meant to ward off the evil's re-entry.
• Your soul can be thrown from your body when you sneeze, and saying bless you prevents your soul from being stolen by Satan or some evil spirit. Thus, bless you or God bless you was used as a sort of shield against evil.
• A sneeze is good luck, and saying "bless you" was no more than recognition of the sneezer's luckiness.

Alternatively, it may be possible that the phrase began rather uninterestingly as a response for an event that wasn't well understood at the time.

Another urban legend states that you cannot open your eyes while you sneeze, or if you manage to your eyes will pop out. This is, as stated, nothing more than an urban legend.

Earliest use

Contrary to the previously mentioned theories, the use of the phrase bless you or god bless you can be seen in literature mentioned long before it supposedly came into common use in English.

"Bless you, my dear!" he said, and "bless you, bless you!" at the second and third sneeze. Apuleius, Golden Ass, AD 150

Dick cannot blow his nose whene'er he pleases, His nose so long is, and his arm so short; Nor ever cries, God bless me! when he sneezes -- He cannot hear so distant a report. Greek Anthology, c. AD 500

Thus, we are left with a little bit of a mystery, as the examples predate the explanations.

Modern use

Regardless of its origins, it is now used in English more as a reaction to a sneeze than a sort of blessing, and it is rarely used with intentional concern for the person's well-being. In many English speaking countries, the German equivalent, gesundheit, is also understood and used in the same way.

In some parts of Australia, the expression is also used when a person belches or breaks wind; this usage is primarily an indication that the blesser has not been offended by the gaseous expulsions of the blessed.

References

1. Opie, Iona, and Moira Tatum. A Dictionary of Superstitions. Oxford University Press; Oxford, 1992. ISBN 0-19-282916-5