LIKE any other criminal justice system, Scots law is much caricatured - sometimes justifiably - as being out of touch and out of date.

Nevertheless, as the prosecution and conviction of Stephen Kelly at the High Court in Glasgow shows, our law can sometimes be flexible and imaginative in adapting to changing times and social conditions.

Kelly was convicted of infecting his former lover with the HIV virus which can lead to full-blown Aids, apparently the first man in Britain to face such a charge.

There is no law in the statute books covering the kind of conduct of which a jury found Kelly guilty and the case against him depended on the tried and tested common law concept of culpable and reckless conduct.

Essentially, the jury decided he had sexual intercourse with his girlfriend while pretending he was not infected and knew he could transmit the virus by having sex. In this day and age, it would be difficult for anyone to argue he did not know he could pass on the HIV virus in this way.

James Drummond Young QC, the Crown prosecutor, provided an excellent summary of the essential ingredients for a charge of culpable and reckless conduct when he told the jury: ''Mr Kelly clearly knew what he was doing and that there was a serious risk of harm (to his girlfriend) but he did it anyway, not caring for the danger which came to pass.''

Nearly 20 years ago, two Glasgow shopkeepers were found guilty of wilfully, culpably and recklessly supplying glue-sniffing kits to children. Defence counsel accepted that this kind of activity was morally repugnant, but argued strenuously that it breached no existing Scots law.

Lord Avonside commented: ''The great strength of our common law in criminal matters is that it can be invoked to fulfil a need. It is not static.''

Old crimes can always be committed in different ways and it would be a surprise if our common law failed to cope with new kinds of criminal conduct, such as computer crime and the supply of drugs which lead to death.

It is probably better than relying on statutory law - such as the dangerous dogs act - which only creates work for lawyers and frequently leads to more problems than it solves.

The only cloud on the horizon may be the human rights act, which is already threatening breach of the peace, that hardy annual of our criminal law, and may be used to challenge charges such as culpable and reckless conduct as too vague.