Perhaps the biggest distinction from his predecessor, Chief Justice Murray ''Smiler'' Gleeson, is that you know when he is being one or the other. Chief Justice Gleeson has a keen, if arctic, sense of humour, but rarely changes expression, and no one has ever dared laugh in front of him just in case he is being serious.

By contrast, Justice French told intellectual property lawyers a few years ago that he had originally studied physics at university, and had been told in his final year, after delivering a seminar on elementary particles and mathematical group theory, that ''you express yourself magnificently, but I am not sure that you know what you are talking about''.

''This encouraged and qualified me to enter the Law School,'' Justice French continued. ''After graduating, I became a lawyer, the kind of person who is the boring imaginary friend of some really interesting people.'' This speech, incidentally, shows another characteristic in common with Chief Justice Gleeson, a tendency to use short sentences rather than long and convoluted ones.

He talked of presiding over a case at which the giving of a patent for Viagra had been challenged as being an ''obvious'' development of known science. ''I was looking forward to an exploration of the ecstasy and mystery of human love. Instead we found ourselves with Pfizer and Eli Lilley on a quest for a 'workable erection'. ''

Robert French is a product of a Jesuit education he was (''alas'', he would say) a fellow student with Alan Fels, one-time head of the Australian Competition and Consumer Commission and blessed with a keen social conscience, which saw him, early in the 1970s, play a leading role in setting up Aboriginal legal services around Western Australia.

His politics then were as a liberal Liberal so that, for some Liberals today, he is a raving leftie ratbag, an impression reinforced by his association with the native title commission, and, if in a more discreet way, his championing of a republic.

In his judgments, however, he is hardly regarded as a judicial adventurer, a phrase he has described as being almost devoid of meaning.

He is certainly conscious of the outcome of his decisions, and more open about the importance and inevitability of choices, but the style of his reasoning is classical, and his reference points black letter law.

He is a regular feature of judicial and legal conferences where his broader attitudes have been rather more on display than in his judgments. In both he shows a keen appreciation of the drift towards centralisation and the sense of Australia as one economy and one nation, if sometimes wistful about loss of local power.

He has also been a thoughtful and watchful commentator on the significance of efforts, through the Council of Australian Governments, to get cooperative approaches to new national problems such as the environment.

He is certainly no fan of the judgment by which the Gleeson High Court may end up best remembered the Wakim decision which seriously crippled the role of the Federal Court.

As one of seven judges with a vote he will struggle, as Justice Gleeson has had to, with the will and the industry of Justice Bill Gummow, a former Federal Court colleague, for a majority on the court.

Yet there are signs that the intellectual dominance of Justice Gummow, and his deeply inward-looking approach, have been in decline since the advent last year of Justice Susan Kiefel, who appears to have pushed Justice Dyson Heydon into dissenting almost as often as Justice Michael Kirby.