Two High Court chief justices may be considered candidates for the title of 'Australia’s Towering Justice’: Sir Owen Dixon and Sir Anthony Mason. Dixon’s claim to the title lies in his articulation of a formalistic doctrinal methodology – ‘Dixonian legalism’ – which held firm for decades. Mason’s claim lies in his unshackling of the Court from legalism, and his reconceptualising of the Court’s role within the Australian system of government. This heralded a form of realism that led to the development of doctrines, some first propounded by Dixon himself, that would progress individual liberties and democratic participation in a constitutional system lacking comprehensive rights protections. This chapter claims that Mason’s legacy is the most important today. His Court’s methodological realism and explicit acknowledgement of values and policy in judicial decision-making, and the doctrinal development that gave the Australian ‘people’ constitutional status and protections, all continue to shape modern constitutional law and debates over the judicial role and method. It is against Mason and the jurisprudence of his Court that modern legalists must now define – and defend – themselves.