The Hollywood police have a perennial problem and must have long ago found the solution. Suppose Cary Grant had got drunk and stabbed his neighbour. Should the police arrest Cary Grant? But that was not his name. His name was Archibald Leach.

Who has committed the crime? Archibald or Cary?

In DPP v Thomas [2006] IEHC the High Court pointed out that, (like Cary Grant), the defendant had chosen to be known by a name other than his real name. Therefore, summonses issued against him in his false name were validly issued and were in time.

What of Kirk Douglas? He changed his name legally to Kirk Douglas, from Issur Danielovitch. (Presumably by deed poll). Has the ground become more certain in his case? Perhaps he does not have a double identity any longer?

In fact, for persons, unlike inanimate things or concepts, double identity is not the usual problem in law; it is the theft of identity. For inanimate things, in law, double identity is common; “public place�, for instance, may have a different meaning in one piece of legislation compared to another.

Identity is not a simple thing. John Locke is credited with the first formulation of identity, in An Essay Concerning Human Understanding (1689), by reference to consciousness rather than the substance of soul or body.

For him, consciousness was memory. This has practical limitations. What of a person suffering from memory loss? If memory defines consciousness, which defines identity, how can we speak of “a person� as suffering memory loss? (This memory loss is different to the memory loss encountered by the Flood/Mahon Tribunal).

More seriously, he denies that identity is related to the body. A body may change and we accept the person has not. A body may have a particular appearance and not reflect the identity of the person. (“Trading Places� is based on this idea).

Possibly, identity is not coincidental with the person. A person may have several “identities�. Some commentators deny that “identity theft� is possible. In their view, what happens is the deception of a person or persons other than the person whose “identity� was stolen.