Gummow first practiced as a solicitor with law firm Allen Allen and Hemsley. He was admitted as a solicitor in 1966 and became a partner of the firm in 1969. He had a diverse practice, including banking law, trusts and revenue law, intellectual property litigation, commercial transactions and some constitutional law.
Barristerial career
After 10 years in practice as a solicitor, Gummow was called to the New South Wales Bar in 1976. At the bar, his practice included equity, commercial, tax and intellectual property matters. It also included large constitutional issues and in several cases he appeared as a junior to then Commonwealth Solicitor-General, Maurice Byers. Gummow was appointed a Queen's Counsel in 1986.
For 30 years, from the year of his graduation until his appointment as a judge, Gummow taught at the Faculty of Law at the University of Sydney. He lectured in equity from 1970 to 1995. Gummow's essay Legal Education emphasised the importance of statutes and legal history; areas he considers were and are insufficiently taught in Australian law schools. He further advocated the need for practitioners in legal education, who were exposed to 'the law in action'. Following his retirement from the High Court of Australia, Gummow was appointed a Professor of the Sydney Law School, where he gives guest lectures, and a Professor at the Australian National UniversityCollege of Law, where he teaches in the constitutional, equity, conflict of laws and refugee law programs.
Jurisprudence
Gummow's judgments are notable for their careful attention to statutory language and context, and are marked by a thorough and scholarly examination of doctrinal history. Gummow is particularly known for his contribution to intellectual property law and equity. Any attempt to select notable judgments of Justice Gummow is made difficult because he is so often a participant in joint judgments, whose authorship cannot be attributed. However, some of his more notable individual opinions include: ', ', ', ', ', ', ', and '. Gummow is also the author of, or participant in, numerous leading judgments in intellectual property law. See, for example: Werner & Co v Bailey Aluminium Products, Advanced Building Systems v Ramset Fasteners, Prestige Group v Dart Industries, ConAgra v McCain Foods. Statistics in recent years have consistently shown Justice Gummow to be most likely to participate or be joined in a majority opinion. He only dissented once in 2006, out of 55 judgments. Justice Gummow also often joins with Justice Hayne; in 2006 this number was 40 joint judgments. Similarly, in the same year Justices Gummow and Hayne joined each other in judgment in all 11 constitutional cases. Michael McHugh, who served on the court with Gummow for ten years, has called Gummow as a "great judicial politician", referring to his ability to convince other justices of the court to join in his opinions.
Publications
Gummow has written extensively and has published numerous essays and articles. He is the author of books including Change and Continuity: Statute, Equity, and Federalism, which is based upon the lectures he delivered at Oxford University in 1999 as part of the Clarendon law lectures series. These lectures take up themes of continuity and change in the law, particularly as they appear in the great common law jurisdictions. He is a co-author of Jacobs' Law of Trusts in Australia, and , the pre-eminent text on equity in Australia. Gummow also wrote, with Dyson Heydon and Robert Austin, several editions of Cases and Materials on Equity and Trusts.
Personal life
Gummow is unmarried and protective of his personal life.
