The number Italians avoid
In Italy, seventeen holds the place that thirteen holds in the English-speaking world. The unlucky date is venerdì 17, Friday the 17th, and some Italians prefer to avoid the number in other settings, such as hotel rooms, floors or seat numbers. Italian practice varies from person to person, and many Italians regard the whole thing as a custom to be joked about rather than obeyed. As elsewhere, it is a belief that some people hold, not a fact about the number.
Italy is also a place where thirteen is not especially feared. The Italian expression fare tredici, “to make thirteen”, is commonly used for a big success. The contrast is a good reminder that number superstitions follow local history and not any universal rule.
The VIXI anagram
The explanation most often given is a matter of Roman numerals. Written in Roman numerals, seventeen is XVII. Rearrange the letters and you can get VIXI. In Latin, vixi means “I have lived”, and the perfect tense implies that the speaker’s life is over. The phrase was used on Roman tombstones and in speech to say that someone was dead. A famous literary example is the dying Dido in Virgil’s Aeneid, who says vixi, “I have lived”. The Roman biographer Plutarch reports that when Cicero announced the execution of the conspirators in the Catiline affair, he used the gentler word vixerunt, “they have lived”, to avoid saying “they are dead”.
So the logic runs: seventeen is written XVII, XVII can be reshuffled into VIXI, and VIXI means “my life is finished”. It is an ingenious explanation, and it explains why the taboo is attached to seventeen, not to some other number.
There are limits to what can be said for it. The anagram only works in Roman numerals, which Italians no longer use for everyday counting, and the explanation requires that people once saw the letters as a hidden message. It is not clear when the explanation first appeared. Ancient Roman writers do not appear to have recorded a rule that the number seventeen was feared, and the claim that the anagram was a Roman taboo is not backed by clear ancient evidence. The idea may well be a later one, made by someone noticing the coincidence of the letters. Roman numerals continued to be used in Italy for centuries, so the explanation is at least plausible for later periods, but plausibility is not proof. It is fair to describe it as the most popular explanation, not the demonstrated one.
Other explanations offered
Because the anagram is a somewhat self-conscious solution, some writers look elsewhere. The main alternative is a biblical one.
- The Flood. In the biblical account in Genesis, the flood is described as beginning on the seventeenth day of the second month. Some writers have suggested that this gave seventeen an association with disaster in Christian Europe. This is a hedged suggestion. The verse is real, but there is no clear evidence that it was the source of an Italian taboo, and the same verse is not the basis for a similar fear elsewhere in Europe.
The existence of more than one explanation is itself informative. When a taboo has several candidate origins and none is documented early, it often means the real origin has been forgotten, and each generation supplies its own reason. The wider habit of reading numbers in scripture is covered under biblical numbers.
Where the habit shows up
In practice the avoidance, where it exists, resembles other conventions. Some Italian airlines are reported to omit row seventeen on aircraft, and some buildings skip the number on a floor or a room. Italian newspapers write about Friday the 17th in the way English-language papers write about Friday the 13th, and the date has furnished jokes and headlines. The parallel with the missing label in a building is instructive, and similar skipping for other reasons is seen in places that follow tetraphobia in East Asia, where four is avoided for a sound-alike reason.
Italian also shows how a superstition can depend on the writing system, not just on the spoken number. The word for seventeen, diciassette, does not sound like anything threatening. Only the written Latin form invites the anagram. That puts the Italian case in a different category from the Chinese sound-based taboos and from the story-based unlucky thirteen of the English-speaking world.
A careful conclusion
What can be said is that seventeen is regarded as unlucky by some Italians, that the VIXI anagram is the standard explanation, and that the anagram is clever but unproven as a historical origin. The biblical alternative is weaker still. It is more accurate to say that the taboo is real as a custom, while its origin is uncertain.