Walking off with the wrong scarf is not theft until you decide to keep it
Picture a diner who grabs someone else's scarf from a restaurant coat rack by mistake. She has physically taken it, yet no crime has occurred, because she believed it was hers. If she later notices the error at home and dishonestly holds on to it anyway, that decision turns an innocent slip into theft.
The example shows the two halves most legal systems demand. The guilty act is taking, keeping or using someone else's property without authority. The guilty mind is dishonesty combined with an intention to deprive the owner permanently. Without both, the matter may still reach court, but as a civil claim such as trespass to chattels or conversion rather than a prosecution.
Definitions differ across jurisdictions. Victoria's Crimes Act 1958 says appropriation means assuming any one of the owner's rights, not all of them, and consent won by deception does not count. Information has been ruled not to be property there. The act defines dishonesty backwards, naming just three honest states of mind: believing you had a legal right, believing the owner would have agreed, or believing the owner could not be found. South Australia's Criminal Consolidation Act 1935 sets up to 10 years in prison for a basic offence and up to 15 for an aggravated one. Canada's Criminal Code, in section 322, even covers depriving an owner only temporarily, and carves out an exception for ore taken for exploration or scientific research.
Motives vary widely. Beyond need or greed, stealing can stem from anger, grief, boredom, compulsion, a wish to fit in with peers, or rebellion, and teenagers who shoplift often cite novelty and peer pressure. The jurists Grotius and Pufendorf held that someone in extreme, unavoidable need who took from the surplus of property holders was not guilty of theft at all.
Religious codes take up the subject too. Buddhism's five precepts forbid taking what is not given, a rule that extends to fraud, cheating and forgery. The Hebrew Bible's Ten Commandments include both a ban on stealing and a ban on coveting.
Source: Theft
