R v Morris; Anderton v Burnside [1984] are English highest court conjoined appeal decisions as to the extent of appropriation that can be considered criminal (as the law of theft is codified in the Theft Act 1968).

Agreeing with Lord Roskill, per curiam (formulating the decision of the whole court), the Law Lords established that in the English law of theft, an appropriation is established if the defendant clearly assumes a right of the owner, that is the prosecution proves such assumption beyond a reasonable doubt.

Burnside was seen to remove a price label £2.73 from a joint of pork and attached it to another (at £6.91).

If a person has substituted on an item of goods displayed in a self-service store a price label showing a lesser price for one showing a greater price, with the intention of paying the lesser price and then pays the lesser price at the till and takes the goods, is there at any stage a 'dishonest appropriation' for the purposes of Section 1 of the Theft Act 1968 and if so, at what point does such appropriation take place.

Lord Roskill in rejecting the defence team's argument, supported by division between "distinguished academic lawyers"[1] said: