From WikiIslam

[edit] Description

Argumentum ad antiquitatem, or appeal to tradition, is a fallacy used to judge an act based entirely on its what was an accepted part of tradition at the time, and not the actual implications thereof. It is often very effective, because it can be cleverly disguised as inference of context. It is, however, an abject fallacy, since traditions have often included witch burnings and human sacrifices - and they are clearly not defendable on mere "context".

[edit] Formula

• X commits Y
• At the time in which X was based, Y was a traditionally acceptable act
• It was therefore acceptable of X to have commited Y

[edit] Examples of Ad antiquitatem

This is often used by Muslims to defend Mohammed's acts, in particular his pedophilia. Muslims assert that it was acceptable at the time, which, even if it were to be true, would be a severely illogical defence, since Mohammed was said to be a paragon for all time. He was also said to have ended other immoral "traditions" (such as infaniticide of unwanted girls), so it raises the questions of why he could not have preached against such an equally deplorable act.

A tradition is not innerant. They are often far from it, as traditions are often based on superstitions and primitivity of earlier cultures, so to grant them moral immunity in such a way is clearly fallacious.