This ploy suggests that the length of time a remedy has been used is a measure of its effectiveness. Its promoters imply that if the remedy didn't work, it wouldn't remain available. Some promoters claim (sometimes truthfully, sometimes not) that their methods have been handed down from generation to generation, are steeped in folk wisdom, were derived from ancient writings, or the like. The falsity of this ploy is easily seen by noting that astrology has survived for thousands of years with no reliable evidence of any validity. Note, too, that many genuine methods survive briefly because they are replaced by more effective ones.