Under Section 1 of the Theft Act 1968, theft is defined as “the dishonest appropriation of property belonging to another with the intention of permanently depriving the other of the property”.
Section 3 (1) defines appropriation as “any assumption by a person of the rights of the owner amounts to an appropriation, and this includes, where he has come by the property (innocently or not) without stealing, any later assumption of a right to the property by keeping or dealing with said property as owner”. The case of R Vs Morris establishes that even an act such as the transference of labels between products in a supermarket can amount to an appropriation whilst the case of R Vs Hinks establishes that appropriation can be committed when consent is obtained dishonestly.
Property is defined under Section 4 (1) as including “money and all other property, real or personal including things in action and other intangible property”. The court may have to decide on whether theft has occurred due to the nature of the property involved.
Section 5 (1) states “Property shall be regarded as belonging to Any person having possession or control, or having said property in any proprietary right or interest”. In addition, Section 5 (3) states “Where a person receives property from or on account of another, and is under an obligation to the other to retain and deal with that property or its proceeds in a particular way, the property or proceeds shall be regarded as belonging to the other”. Similarly, Section 5 (4) details that “ where a person obtains property by another’s mistake, and is under an obligation to make restoration of the property or its proceeds, that property is regarded as belonging to the person entitled to restoration. Therefore an intention not to make restoration shall be regarded as an intention to deprive that person of the property or proceeds”. In the case of Attorney General’s Reference 1 (1983), the defendant was paid an excessive amount of wages and did not return them. She was guilty of theft as she had no intention of making restoration of the property when obtained by mistake even though she had an obligation to.
Dishonesty has no definition in the Theft Act 1968, which has led to the use of an objective test established in the case of R Vs Ghosh. This involves the court deciding whether “the behaviour of the defendant would be regarded as dishonest by the ordinary standards of honest and reasonable people” and whether “the defendant realised their conduct was dishonest by those standards”.
Section 6 (1) details “ A person appropriating property belonging to another without meaning the other permanently to lose the thing itself is nevertheless to be regarded as having the intention of permanently depriving the other of it if his intention is to treat the thing as his own to dispose of regardless of the others rights and a borrowing or lending of said property may amount to so treating it if the borrowing or lending is for a period and in circumstances making it equivalent to an outright taking or disposal”. The case of R Vs Velumyl establishes that intention to permanently deprive is present when the exact property cannot be replaced.
The Theft Act 1968 does not provide a legal definition of “dishonest”. The lack of legislative clarity on this term may result in confusion on how it is to be interpreted in law. This may then lead to an inconsistent application of it, with different cases providing conflicting interpretations (Ghosh , Feely  and Lightfoot ) for how these problems manifest in practice. It will also mean that the interpretation of the word will largely, alongside judges, be left to the discretion of jurors. Legal academics have criticised this, with Sir Brian McKenna saying “it is surely better that these questions should be decided not by juries but by Parliament”.
-The Ghost Test formulated in Ghosh  creates a two-fold test for defining the meaning of “dishonest”, containing an objective and subjective test. This is self-contradictory and potentially confusing for legally-unqualified jurors who are unfamiliar with the complexities of both tests. Law Reform bodies, such as the Law Commission, have also argued that the test should be codified in statute to make the test more transparent and intelligible. Critics have argued that if the Theft Act 1968 had originally explained the meaning of “dishonest”, such problems would not have arose.
An argument has been made that the word “appropriates”, contained with Section 1(1), is defined too widely. Prior to the 1968 Act, the English Law required the physical taking of property for an appropriation to be constituted. Following the 1968 Act, and resultant case law, this is no longer the position. Section 3(1) states “Any assumption by a person of the rights of an owner amounts to an appropriation”. Rights include to take, use, sell, destroy or damage, wear and lend. In effect, a theft, according to the legislative meaning of ‘appropriates’, may be performed if a person merely wears or uses the property temporarily. This assumption is confirmed by the concluding words in Section 3(1) of the act – “this includes, where he has come by the property…without stealing it”. Interpreting a theft this loosely leads to an absurd legal meaning of what a “theft” is, undoubtedly contradictory to the Rule of Law as “the law should be certain”.
The case of Hinks  broadened the meaning of “appropriates” to include where a person has been given a gift by another person, or what is legally called “the acquisition of an indefeasible title to property”. Gomez  and Lawrence  also advocate that an unlawful appropriation may occur even when the person has consent to appropriate by the owner. All three cases have arguably made redundant the logical meaning of “appropriates”.
Section 6(1) allows borrowing or lending to constitute an “intention of permanently depriving”. Clearly, an intention to temporarily borrow or lend is not an equivalent of, or similar to, an intention to temporarily borrow. It is arguably wrong to include borrowing or lending within the section. The later words within this section “in circumstances making it equivalent to an outright taking or disposal” are also somewhat ambiguous.