Caisley's documented life is centred on Sydney, the capital of New South Wales, where he completed his university studies and later practised law. His legal career therefore developed within the Australian legal system, in which admission to the bar in Australia was the formal point of entry into practice.
Caisley studied at the University of Sydney, where he obtained the degrees of Bachelor of Arts and Bachelor of Laws. Established in 1850, the university was Australia's first university, and it became one of the country's principal centres of higher learning in the nineteenth and early twentieth centuries.
The university's formal law teaching took shape in 1890, when William Pitt Cobbett was appointed to the inaugural Challis Chair of Law. He became the faculty's first dean in 1891 and lectured in jurisprudence, Roman law, constitutional law and international law. The faculty established in 1890 is now known as Sydney Law School.
Caisley was admitted to the bar in Australia in 1965. His documented professional career is associated with Phillips Fox, where he worked as a partner in Sydney.
Phillips Fox traced its roots to Melbourne practices, including the established firm Phillips Fox & Masel, whose agency relationships with other practices led to a series of combinations. The firm subsequently operated under the collective name Phillips Fox and became the first national law firm in Australia. It was regarded as one of the country's most progressive and respected legal practices, and its national structure was designed to serve clients whose business extended beyond state and national boundaries.
The firm later appeared under the name DLA Phillips Fox and was connected with the international DLA Piper network from November 2006. Phillips Fox was dissolved as a separate law firm in May 2011.
