He was born in Melbourne to James Chester Guest, a business manager and Chairman of the Commercial Bank of Australia, and Patricia, née Hammond.
A graduate of Geelong Grammar School, he attended Brasenose College at Oxford University, where he received a Master of Arts; he became a barrister-at-law in Lincoln's Inn in 1960.
From 1961 he was an associate to Sir Owen Dixon, Chief Justice of Australia; in 1963 he returned to Victoria as a barrister.
[2] Though never on the front bench in government he followed his circulation of lengthy policy papers as a new member by taking the leading part in reform of public sector superannuation as a member of parliamentary committees in Opposition while writing innovative policies for the Arts and Federal Affairs as a Shadow Minister and taking an influential part in both extending the scope for Upper House committees and, as a member of a sub-committee of the Australian Constitutional Convention influencing the report on the powers of the Governor-General.
Under the Kennett government he was Chairman of the Parliamentary Law Reform Committee and as such responsible for substantial reports on Reforming the Law of Wills[3], Health Services and Legal Liability, Phoenix companies and the Jury system involving study of jury systems in situ in six countries.