There Runs the Quick Perspective of the Future, 
Where to From Here?
The rule of law and the nature of judicial power
Robert French AC Oration 2022
delivered by Justice Craig Colvin

It is an honour and a privilege to be invited to deliver the Robert French AC Oration this evening. To be asked to do so by a conjunction comprising the Hellenic Australian Lawyers Association, the Asian Australian Lawyers Association and the WA Society of Jewish Jurists and Lawyers testifies to the breadth of the esteem in which the former Chief Justice is held amongst the legal community. It is also a small manifestation of the rich cultural diversity of modern Australia in which I take some personal delight. It causes me to reflect on what it means to have a sense of who you are and where you fit in. The ideas, beliefs and culture that we share with others give rise to a deep sense of belonging. They confer the identity that is constituted by shared values.
Identity is a cousin to dignity. To deny its existence in the name of integration or assimilation or sovereignty is a form of oppression. When we celebrate diverse identities we confer dignity, we strengthen our cultural commonwealth and we reinforce our sense of society. Always though, the challenge is to maintain our own identity whilst also recognising the worth of others. Without the latter, identity foments division. With it, we become more than we would otherwise be. We embrace the possibility that although we are not the same, yet we are. Our sense of who we are expands to include those with whom we might, at first, fail to identify. And we work against the politics of identity that seeks to fragment by denying dignity to others.
So, I begin by acknowledging the traditional custodians of the land we meet on this evening, the Whadjuk people. I acknowledge their continuing culture and the contribution they make to the life of this city and this region. I recognise the strength and resilience of all Noongar people and their spiritual connection to this place. I pay my respects to Aboriginal Elders past, present and emerging. 
Half a century ago, a young Robert French was amongst those who were instrumental in establishing the Aboriginal Legal Service in this State. That early role in his life as a lawyer is a measure of the man and his perspective on what is needed for the law to be just in its administration. Then, Aboriginal people were rarely represented before the courts, particularly those presided over by country magistrates. So far as I am aware, they were not yet counted amongst the lawyers who could appear and were a long way from being represented amongst its judges.
At that time, there was also the beginning of a land rights movement which took a whole new direction 20 years later with the Mabo decision and the subsequent establishment of the National Native Title Tribunal with Justice French as its inaugural head. The recognition of native title brought a restored foundation for Aboriginal people to live out their culture and connection to country. The radical change that had been effected by the assertion of British sovereignty was shifted in a way that would substantially alter our mutual sense of identity. 
I am confident that 50 years ago many people, including those in the legal community, saw no injustice in the land tenure circumstances that then prevailed. Less still would those circumstances have been seen to be contrary to the rule of law. Indeed, I venture to suggest that back then most lawyers would have said that, in its application to the land claims of Indigenous Australians, the rule of law was being upheld in Australia. 
However, the perspectives of that time rested entirely upon a common law rule which assumed that there was no normative system of law in Australia before the declaration of British sovereignty. That rule 'took from indigenous inhabitants any right to occupy their traditional land, exposed them to deprivation of the religious, cultural and economic sustenance which the land provides, vested the land effectively in the control of the Imperial authorities without any right to compensation and made the indigenous inhabitants intruders in their own homes and mendicants for a place to live'. 
Those powerful words, expressing succinctly how then established common law principle applied to First Nations people, were crafted by Brennan J, one of Australia's finest jurists, to expose what was at issue in the Mabo case. They sit at the heart of the reasoning by his Honour in the case. 
They were followed by this description of the principle of terra nullius:
Judged by any civilized standard, such a law is unjust and its claim to be part of the common law to be applied in contemporary Australia must be questioned. 
By that point in the reasons, there can be no doubt to the reader as to what was at stake. Nevertheless, Brennan J went on to invoke a form of constitutional sentinel:
In discharging its duty to declare the common law of Australia, this Court is not free to adopt rules that accord with contemporary notions of justice and human rights if their adoption would fracture the skeleton of principle which gives the body of our law its shape and internal consistency. 
This, I believe, is a reference to all that is bound up in the notion of the rule of law. It is the 'skeleton of principle' which gives our law its shape and internal consistency. Brennan J was reminding himself of the limits upon the extent to which resort to matters of fundamental principle may be called upon to justify a decision to change the content of a common law rule. Significantly, he did so by stating what cannot be done by the courts. His Honour did not appeal to contemporary notions of what the law should be as a matter of policy. Rather, he began by keeping watch on the limits of judicial power. He expressed those limits in terms of 'contemporary notions of justice and human rights'. This is a phrase to which I propose to return.
Having exposed in the starkest of terms the injustice that flows from the application of the notion of terra nullius his Honour did not rest upon that position as a basis for the decision. Instead, he proceeded to ask pointedly whether adherence to existing common law principle 'seriously offends the values of justice and human rights (especially equality before the law) which are aspirations of the contemporary Australian legal system'. In doing so, his Honour was not invoking the views of contemporary Australians concerning customary title or claiming to know them. Nor was he deciding what the common law should be by reference to his own sense of what would be just or right. Rather, he was appealing to that which is embedded in the doctrines of the common law, that which lies at its foundation and provides its architectural integrity. He was describing that attribute of the law as administered by the courts that seeks to align the content of the law with all that forms part of a contemporary understanding of the rule of law, relevantly the principle that there is equality before the law. 
It is the respect in which the concept of the rule of law informs the nature and extent of judicial power that I propose to address this evening.
The Mabo decision led to uproar from certain parts of the Australian community. However, now, 30 years on, there is considerable, though it must be said not universal, support for where we have arrived and where we are headed. I venture to suggest that a significant majority of Australians understand that it would be fundamentally unjust to go back. That is because the old common law principle was deeply inconsistent with adherence to the rule of law. It was therefore unable to be maintained as part of a common law system founded on that bedrock. 
The Mabo decision has also led to a much broader recognition within Australian society of the long history of the country before European colonisation. It enabled then Chief Justice French, on the occasion of his swearing-in to that office, to say: 'The history of Australia's indigenous people dwarfs, in its temporal sweep, the history that gave rise to the Constitution under which this court was created. Our awareness and recognition of that history is becoming, if it has not already become, part of our national identity'.
My own experience of his Honour's exercise of judicial power was principally as a judge of the Federal Court. His intellect was both precocious and prodigious in its capacity. His Honour wrote formative decisions in the Court's then emerging trade practices jurisdiction and also in administrative law, including the Tampa appeal concerning executive power. Extra-judicially, his Honour had an eye to pop-culture references. The observant may see the influence of his background in science and his interest in science fiction. 
I interrupt these sentiments to say that he also inflicted my most devastating defeat in a case concerned with airlines and market definition. It is a result I do not hold against him because I must say unreservedly that it was always a pleasure to appear before Justice French. I found him to be an inquiring judge who was always in search of the best that your argument might reveal. Even in defeat there was the satisfaction of seeing your contentions understood, indeed improved upon. Always there was a search for underlying principle rather than simple reference to precedent. It is a perspective that pervades his decisions. As a judge, Robert French thought deeply about the essential characteristics of our federal legal system. All was placed in its proper context and approached with due caution. Beneath it all there was, and still is, the embodiment of a genuine enthusiasm for the law and what it should be. 
I hope these further remarks are worthy of his own eminence in contributing to the decisions and discourse I am about to briefly address.
There is, as Cicero recognised, a respect in which there is a single and unchangeable sense of justice that applies to all peoples for all times.  Our ability to reason, the divine spark that we share, unites us and causes most of us to name the same core principles. We are all capable of being moved in the same way by acts of kindness, generosity and goodness. These things are fundamental. They manifest in our desire for fairness and dignity. They allow space for mercy. As to all that really matters, truly there is no essential difference between us. The consequence is our shared sense of the human condition. 
As Cicero said, 'we are all born for justice' and 'nothing can be honourable if justice is absent'. 'Justice is the crowning glory of virtue'. Its substance consists in doing no injury or wrong to any person. It 'does not descend from a pinnacle' and 'is observed even to the lowest'. It recognises that 'liberty is to be preferred to all things' and that 'only where the power of the people is supreme has liberty any abode'. 
In this oratory from two millennia ago we immediately recognise justice being described in terms of the rule of law. However, of equal significance is the fact that its fundamental rationale rests upon a shared sense of identity, the divine spark of reason that enables us to see ourselves in others. It is that foundation that led Cicero to describe justice in terms that require rule by laws that apply in the same way to all and not by the exercise of unqualified power entrusted to an emperor or to governing elites.
Importantly, the fundamental justification for the rule of law is the equal standing of each person as a citizen of the society being administered. Such equal standing requires a shared sense of identity. It is not possible to separate the justification for the rule of law from this understanding. It gives rise to the essential qualities of the justice that must be administered in the courts of a legal system where the rule of law is observed.
From time to time, we are forced to confront the status quo of a legal rule or an attribute of the manner of exercise of judicial power. There may even be instances where we see that, despite the benefit, status, power or authority that the law or its judicial administration affords us, or people like us, the way in which the law affects others cannot be justified. All the more so where the law marginalises or discriminates. Then we are moved by the evident injustice to question the law's validity.
Within a governmental structure of the kind embodied in our own Constitution we look to the legislature to enact our laws. It would be inconsistent with the rule of law if the judiciary were to assert a general law making power. However, like all generalisations, these propositions fail to recognise important qualifications. Indeed, there are respects in which the qualifications are fundamental to the rule of law.
In Australia, some aspects of the content of legal rules observed and given effect by the courts are not derived from the legislature.  First and foremost there are the limits upon the constitutional authority of the legislature, the executive and the judiciary to be found in the Constitution. Importantly though, as the experience of the United Kingdom exposes, within a common law system founded on the rule of law certain of those limits exist even if there is no written constitution. 
Secondly and relatedly, there is the integrity of the courts. In a series of decisions made during the tenure of French CJ, particular attributes of state and federal courts have been determined to be constitutionally entrenched. They include the supervisory jurisdiction in respect of the validity of administrative or executive action and the judicial character of the decisions to be made by those courts. The content of those matters is set by the High Court and not by the legislature. By investing judicial power in courts, the Constitution impliedly requires that those courts 'exhibit the essential attributes of a court and observe, in the exercise of judicial power, the essential requirement of the curial process, including the obligation to act judicially'. 
However, there are at least four respects in which the specific content of the law administered by the courts where that content is determined by the courts. They include (a) the content of the essential jurisdiction to determine whether the actions of public officials exceed lawful authority; (b) the content of the rules by which the laws of Parliament are to be interpreted; (c) the content of the common law (recognising that Parliament may also legislate as to the content of the common law); and (d) the content of what is required by way of judicial deliberation and reasoning.  More complex is the position in relation to the making of court rules of practice and procedure, the concurrent conferral of administrative power upon judicial officers and the delegation of judicial power. Nevertheless, there are aspects in which the content of the legal rules as to these matters is a matter for the courts not Parliament.
Each of these matters forms part of a genus of instances where the subject at issue is the nature and extent of judicial power and its exercise. If the content of the principles as to these matters could be set by Parliament then there would be the potential for the authority of the courts to be curtailed by legislation. In short, if the courts are to retain their integrity as part of a legal system that conforms to the rule of law then, in certain respects, it is the courts themselves that must be able to make the rules to ensure that is so. 
My thesis is that when it comes to matters that bear upon the nature and extent of judicial power, the courts must resort to the rule of law in formulating the legal principles to be applied in dealing with these aspects of the administration of the law. This is where these principles find both their source and legitimacy. The reasoning of Brennan J in Mabo concerning the circumstances in which the common law rule of terra nullius may be revised is an example of such an instance, but there are others.
Before I consider some examples, let us remind ourselves of what we mean by the rule of law. I do not mean to be exhaustive. I simply wish to state the basic attributes usually embraced by the expression.
Every law should be binding on every person in the same way. Laws should not be made or administered in secret. They should be accessible, known in advance and expressed in clear terms. They should identify the limits of any authority conferred by them. Their prescriptions should be reasonably capable of obedience. Laws should not take the form of unconstrained discretion or wholesale delegation. There should be accountability as to the administration of the law. The lawfulness of actions should be adjudged by an independent judiciary deciding cases in public after a fair hearing and by publishing reasons for their decisions. In a modern democracy, we usually add a further requirement that the making of laws, their execution and their interpretation should be separated. In addition, I note that there are also those who view the rule of law as also requiring the diversity of the community being administered to be reflected in those who participate in the making, administration and adjudication of the law.
Importantly, none of these matters concern the content of the laws that might be made. Rather they concern the required source and characteristics of all laws irrespective of their content and the way they are to be administered.
There is debate as to whether the notion of the rule of law extends to the content of law, particularly what might be described as the embodiment of a bill of rights. Dworkin and other substantivists would recognise the need for some intrinsic or fundamental human rights to be recognised before a legal system could be recognised as fulfilling the description 'rule of law'. The difficulty is that such an approach leads immediately to an attempt at the enumeration of those human rights and traps their content under glass. It also requires the judiciary to traverse the field of policy. As the contemporary experience of the United States illustrates, there may be deep divisions concerning the content of such rights and society's perspective upon them may shift substantially over time. In the analysis of common law systems, this debate fails to recognise the mechanisms by which the common law embodies and protects fundamental freedoms without enumerating or codifying them. 
For present purposes, I propose to differentiate between three distinct categories of attributes in understanding the rule of law.
First, there are those attributes of a legal system which the rule of law requires irrespective of the content of the law. They include the separation of powers. I will refer to these aspects as constitutional. 
Second, there are those attributes of the content of the law that must exist in order for the law as administered to reflect those foundational rights and freedoms which are firmly recognised by and entrenched within the particular society that is administered according to the rule of law. I will refer to these aspects as foundational.
Third, there are those attributes of the content of the law that might be described by some as fundamental rights and freedoms, but about which there is either a divergence of views as to whether they are properly considered to be fundamental rights or freedoms or a significant field of ongoing policy choices to be made as to the content of laws informed by a general recognition of those rights or freedoms. I will refer to these aspects as contestable.
To illustrate these distinctions, the requirements that laws apply equally, are publicly known and administered, and are not to be imposed retrospectively, would be constitutional. The requirements that no law may provide for arbitrary executive detention, that a person is presumed innocent until proven guilty according to law and that there should be freedom to criticise the government are foundational. Requirements to the effect that the sanctity of life should be protected, there is a right to free speech or there is a right to own a gun are contestable. For reasons I will seek to explain, the distinctions have significance when it comes to the role of the courts in giving effect to the rule of law.
I must say immediately that neither constitutional nor foundational aspects of the rule of law are absolute in the sense that they recognise no exception or qualification. Rather, the field of exceptions is generally well understood and principled and does not depend upon policy judgments. For example, there are instances where retrospective laws or laws permitting a broad discretion as to the making of regulations may be justified. However, the justifications do not depend upon uncertainty or debate as to what the rule of law requires. 
This is not surprising because the rule of law is not itself a law. Rather, it is a philosophical underpinning that works foundationally. It is a kind of morality that must be instilled in the minds of those in authority and embedded in the institutions of government. 
Finally, whether a rule of law requirement might be categorised as constitutional, foundational or contestable is not static. In the course of our own history and the history of other societies the extent to which rights and freedoms have been recognised as fundamental has changed. At the time of Magna Carta, freedom of religion was contestable but it gradually became foundational in our society. Similarly, over time, social movements for the abolition of slavery, the recognition of the right of labour to organise, the emancipation of women and the proscription of racial discrimination have moved those matters from being contestable to foundational. Indeed, a requirement that all laws treat every individual as having an identity as a person rather than as a chattel might now be said to be constitutional in the sense that every law must take that form irrespective of its content. Likewise, the extent to which a requirement that the authority to make law not be delegated might be considered constitutional has changed over time.
Let me now explore the significance of these distinctions for the way the courts use the rule of law. 
The High Court has rejected the approach that a conception of the 'rule of law' might itself be treated as if it were contained in the Constitution. Rather, it recognises the rule of law as a complex foundational idea that informs an understanding of both the nature of the governmental institutions that it establishes and the relationship between them. In that way it may inform the meaning to be given to the provisions of the Constitution, especially those which concern the distinctions between legislative, executive and judicial power. 
In the recent decision of Palmer v Western Australia, the High Court rejected Mr Palmer's attempt to call in aid the rule of law as a cardinal principle said to have been infringed by Western Australian legislation restricting freedom of movement during the COVID pandemic. The plurality said:
'The rule of law' is a useful shorthand description of a complex concept central to an appreciation of the form of government that inheres in the text and structure of the Constitution. Acknowledged repeatedly has been that the Constitution was framed on the 'assumption' of the rule of law. Reference to the rule of law can help to elucidate the scope and operation of a conferral of judicial power, just as it can help to elucidate the scope and operation of an express or implied limitation on legislative or executive power.
I respectfully suggest that this is to refer to the constitutional aspect of the rule of law which I have described. It is why its insight may support a freedom of political communication that does not extend to a general right of free speech. 
These matters are also reflected in the common law constitutional position in the United Kingdom. There, resort to the rule of law is the means by which the content of unwritten constitutional principles may be identified. This does not appropriate to the courts authority to entrench any of those contestable aspects of a 'thick' rule of law which concern the content of fundamental human rights. Rather, it is concerned which the constitutional and the foundational aspects of the rule of law that I have described. 
So, when the time came for the reform of the Office of Lord Chancellor and the establishment of a truly independent Supreme Court, the Constitutional Reform Act 2005 (UK) began by stating that the existing constitutional principle of the rule of law was not adversely affected by the legislation. This reflects the sense in which an unwritten constitution may embody matters of constitutional and foundational principle captured in the notion of the rule of law. It is not to say that the rule of law is itself some kind of a law. 
Similarly, the High Court's approach to the content of the entrenched jurisdiction of the courts to review the lawfulness of administrative and executive action reflects its character as giving effect to the rule of law. As Brennan J said, in Church of Scientology v Woodward:
Judicial review is neither more nor less than the enforcement of the rule of law over executive action; it is the means by which executive action is prevented from exceeding the powers and functions assigned to the executive by law and the interests of the individual are protected accordingly.
In the recent decision in MZAPC, the plurality explained the modern conception of jurisdictional error as being 'rooted in our constitutional history' an aspect that is now expressly 'articulated as an explanation of the scope of the Court's entrenched original jurisdiction to engage in judicial review'. I suggest that the Court is referring to what I have described as the constitutional aspects of the rule of law that are embedded in the governmental institutions preserved by our own Constitution but which also exist within the unwritten constitutional framework of the common law.
It is a perspective evident in the following statement from Re Bolton; Ex Parte Beane:
Many of our fundamental freedoms are guaranteed by ancient principles of the common law r by ancient statutes which are so much a part of the accepted constitutional framework that their terms, if not their very existence, may be overlooked until a case arises which evokes their contemporary and undiminished force.
Further, resort to the rule of law as the philosophical underpinning of the Constitution exposes the significance of all that flows from entrenching the existence of the courts by its terms. The existence of authority on the part of the courts to review the lawfulness of administrative and executive action (as well as the ability to determine the content of that authority) is essential to the rule of law. It is fundamental to the character of the courts within a society administered according to the rule of law. The limits on that authority are determined by the extent of what I have described as the constitutional and fundamental aspects of the rule of law. Importantly, the entrenched existence of the courts is not a foundation for a review jurisdiction to protect contestable aspects of the content of the rule of law. To do so would be to assume a need to consider competing policy positions and to assume a legislative function.
Further, in any case where the source of administrative authority is to be found in the terms of legislation, it is the rules of statutory construction that determine the extent of the authority conferred by Parliament. The content of those rules is also within that genus of rules which concern the nature and extent of judicial power. 
As to the significance of those rules, in MZAPC their Honours observed that:
The statutory limits of the decision-making authority conferred by a statute are determined as an exercise in statutory interpretation informed by evolving common law principles of statutory interpretation.
The reference to the 'evolving common law principles of statutory construction' is significant. It recognises that those rules must evolve in order to meet contemporaneous circumstances and thereby properly fulfil their constitutional function. Though there described as 'common law principles', they are not like those aspects of the common law which express the content of rules, such as the content of contract law or the law of negligence.  Rather, constitutional aspects of the rule of law require that the rules of statutory construction embody and reinforce the distinct roles of the legislature and the judiciary. So, the courts must not, in the name of interpreting law, become law makers. However, equally, the legislature must not in the form in which it enacts a law, express provisions of a kind or in a manner that does not conform to that which is required by the constitutional and foundational aspects of the rule of law. 
The rules of statutory construction afford the principled means by which the courts ensure that laws have the fundamental attributes to be expected of all laws in a society administered according to the rule of law and only depart from those fundamental attributes where there is proper justification to do so. Therefore, the content of the rules of statutory construction must be formulated by reference to the attributes of the rule of law. Let me give some examples of how this is done.
I will begin by using the principle of legality to illustrate. 
In 1908, the High Court expressed the principle in the following terms:
It is in the last degree improbable that the legislature would overthrow fundamental principles, infringe rights, or depart from the general system of law, without expressing its intention with irresistible clearness.
Notice the reference to 'fundamental principles' and 'the general system of law'. 
By 1994 a majority of the High Court said:
The insistence on express authorization of an abrogation or curtailment of a fundamental right, freedom or immunity must be understood as a requirement for some manifestation or indication that the legislature has not only directed its attention to the question of the abrogation or curtailment of such basic rights, freedoms or immunities but has also determined upon abrogation or curtailment of them. The courts should not impute to the legislature an intention to interfere with fundamental rights. Such an intention must be clearly manifested by unmistakeable and unambiguous language. General words will rarely be sufficient for that purpose if they do not specifically deal with the question because, in the context in which they appear, they will often be ambiguous on the aspect of interference with fundamental rights. 
By this point, we see the principle expressed in terms of fundamental rights, freedoms or immunities.
At about the same time, in the United Kingdom the principle of legality was expressed to be constitutional in character by Lord Hoffman. As his Lordship said:
Fundamental rights cannot be overridden by general or ambiguous words. This is because there is too great a risk that the full implications of their unqualified meaning may have passed unnoticed in the democratic process. In the absence of express language or necessary implication to the contrary, the courts therefore presume that even the most general words were intended to be subject to the basic rights of the individual. In this way the courts of the United Kingdom, though acknowledging the sovereignty of Parliament, apply principles of constitutionality little different from those which exist in countries where the power of the legislature is expressly limited by a constitutional document.
In 2004, Gleeson CJ identified the rule of law as the foundation for principle of legality when his Honour said: 
The presumption is not merely a common sense guide to what a Parliament in a liberal democracy is likely to have intended; it is a working hypothesis, the existence of which is known both to Parliament and the courts, upon which statutory language will be interpreted. The hypothesis is an aspect of the rule of law.
In the same year, Gleeson CJ reasoned in Al-Kateb:
A statement concerning the improbability that Parliament would abrogate fundamental rights by the use of general or ambiguous words is not a factual prediction, capable of being verified or falsified by a survey of public opinion. In a free society, under the rule of law, it is an expression of a legal value, respected by the courts, and acknowledged by the courts to be respected by Parliament.
It can be seen that in the United Kingdom the principle is expressed as constitutional. In Australia it is seen as a reflection of the rule of law in the principles of statutory construction. Nevertheless, for reasons I have given, it may have a constitutional aspect to the extent that it is seen to form part of the entrenched attributes of a court exercising judicial power. Even so, the rule as formulated has a significant attribute. It recognises the ultimate authority of Parliament to enact a law that would abrogate fundamental rights, provided it is constitutional. 
I will leave for another day whether the entrenched character of a court means that the courts have authority to determine that a law is invalid by reason that it lacks the constitutional attributes required by the rule of law and does so without evident justification. It appears that some would argue for that position as part of the unwritten constitutional principles of the United Kingdom. In South Australia v Totani, French CJ expressed the view that it is self-evident that it is beyond the power of the courts to maintain unimpaired common law freedoms which an Australian Parliament, acting constitutionally, has abrogated, restricted or qualified. However, note the important qualifier that refers to the Parliament acting 'constitutionally'. 
Significantly, the fundamental rights in respect of which the principle of legality have been invoked, fall within those aspects of the rule of law that I have described as constitutional and fundamental. In the schedule, I have listed the particular rights, freedoms and immunities in respect of which the High Court has invoked the principle of legality. I suggest that none of them stray into what I have described as the contestable aspects of the rule of law.
Similarly justified is the principle of statutory construction by which it can be assumed that clear language must be used to alter retrospectively existing legal rules on which people have ordered their affairs.
These observations also account for the repeated statements by the High Court to the effect that the application of the principles of statutory interpretation is constitutional in character. It has been said that 'the fundamental duty of the Court is to give meaning to the legislative command according to the terms in which it has been expressed'. The application of established rules of construction so as to give effect in an objective way to the manifestation of the intention of the legislature through the particular words used has been described as an important expression of the constitutional relationship between the arms of government. They are also described as rules that are 'accepted by all arms of government within the system of representative democracy'.
The content of the rule of law has significance in the interpretation of legislation in other ways. It provides the conceptual source for various obligations and limits that generally are to be implied into statutory provisions. A well-known example concerns procedural fairness. The common law usually will imply a condition that a power conferred by a statute on the executive branch be exercised with procedural fairness to those whose interests may be adversely affected by the exercise of that power. In Kioa v West, Brennan J explained how all statutes are construed against a background of common law notions of justice and fairness explaining that when a statute does not expressly require that the principles of natural justice be observed, the court construes the statute on the footing that 'the justice of the common law will supply the omission of the legislature'. His Honour's description of the principle was quoted with approval in Saeed v Minister for Immigration and Citizenship. Again, this appears to be an invocation of the way the rule of law is embedded in the common law, particularly as to its constitutional and fundamental aspects. 
Where a statute requires something to be done but no time is fixed it may be determined as a matter of statutory construction that it must be done within a reasonable period of time. Similarly, a requirement of legal reasonableness in the exercise of a power entrusted to a decision-maker is derived by implication from the statute. These principles work against laws that would allow a form of arbitrariness in the law's administration that would be contrary to the constitutional aspects of the rule of law.
So too, it is now recognised that a statute is ordinarily to be interpreted as incorporating a threshold of materiality in the event of non-compliance. An immaterial failure to conform to the requirements of the statute will not result in invalidity. The principle ensures that  resort to technicality does not defeat the integrity of the rule of law. It recognises that common law principles of statutory construction rest on a common sense understanding of what Parliament is likely to have intended.
Now, to return to the reasons of Brennan J in Mabo and his Honour's reference to 'contemporary notions of justice and human rights' with which the common law must conform. I suggest that his Honour had in mind both the constitutional and foundational requirements of the rule of law, but importantly, not its contestable aspects. The reasons of Brennan J were not appealing to the content of some fundamental human right that might be found in some charter or declaration or prevailing public sentiment. Rather, his Honour was directing attention to the need for the common law to manifest in the content of its rules those constitutional aspects of the rule of law as well as the attributes that were established within the skeleton of its principles as being foundational. This is to appeal to entrenched characteristics of the rule of law.
This can be seen when attention is paid to what was at issue in Mabo. No Parliament had enacted the principle of terra nullius. It was a creature of the common law. The High Court has the ultimate authority to determine the content of the common law of Australia. The principle of terra nullius was fundamentally unequal in its application because it denied the existence of the customary connection to land of Australia's original inhabitants irrespective of whether there had been any legal step taken to extinguish that connection. It was a law focussed in its effect upon First Nations people and it applied to them a rule based upon asserted fact that could not be disputed by evidence that might be adjudicated by a court. It operated to foreclose any claim, even those claims which were not extinguished by a proper understanding of the legal effect of the declaration of sovereignty. It denied by law, not judicial determination, the factual existence of both a culture and a spirituality that recognised the connection of particular people to particular areas of land.
Importantly, the reasoning in Mabo did not rest upon a judicial claim to authority to change the law to reflect a policy choice as to the content of the law. The argument may be made that such choices are a matter for Parliament and the executive within the extent of its authority even where they concern a change in established common law rules. Political authority to govern confers the power to make the necessary policy decisions in the best interests of the people as to what the law should be. The exercise of that power is made accountable by regular elections. 
However, the reasoning in Mabo did not enter upon that field. Rather, it gave effect to an understanding that the maintenance of the rule of law depends upon the common law being constructed on the skeleton of principle that is captured in the constitutional and fundamental aspects of the notion of the rule of law. For the courts to continue to administer common law principles that did not conform to those aspects of the rule of law would itself be to fail to adhere to the rule of law. There being no justification for an absolute rule that denied the justiciability of the existence of connections to land that had the character of customary title supported by a system of customary law, terra nullius was a law that could not be sustained as part of a common law system founded on the rule of law.
Of course Parliament could, and did, enact a law concerning native title. In doing so, it enacted laws to which the courts were required to give effect, to the extent that those laws conformed to the Constitution. The courts would do so by performing the constitutional function of interpreting those laws according to the principles of statutory construction. 
Which brings me, finally, to some brief observations about the future.
In the common law system, the ascension of the rule of law was gradual. Its existence was fully revealed with the publication of Prof A V Dicey's seminal text. As I have sought to explain, its character is neither immutable nor externally sourced. This gives rise to some important ongoing consequences.
The sustenance of the rule of law depends upon the maintenance of the fundamental character of the very same institutions that brought it into existence. That responsibility lies with the members of its Parliament, the ministers of its Executive and the judges of its Courts. This is not done by making rules about its content. Rather, it is done by continually narrating its characteristics, finding the language to describe its essential content and guarding against incursions. 
Just as the notion that the King ruled with divine authority infected the whole legal order with a distinctly theological character, so too the notion of the rule of law flavours all laws. The constitution of a nation that is founded on the rule of law, whether written or unwritten, will embody its characteristics. However, the language of its articles will not be enough. Those articles must themselves be viewed as giving effect to the rule of law. They must be understood and carried into effect by decisions that have at their core a keen insight into what it means for the whole system of government to be founded on the rule of law.
It is often said that the strength of the common law is its origin in practical and just resolution of individual cases gradually building into principle. However, its strength also enures in the way it has embodied the rule of law. 
The rule of law depends upon a system that is capable of producing and maintaining itself. Just like the chemistry of living cells, the rule of law must have an autopoietic character. Its institutions must be self-sustaining, self-limiting and self-correcting. That is to say, the form of institutions of government and the actors within government must each resort to the rule of law to inspire and guide their characteristics and actions.
There are fundamental respects in which the rule of law does not allow us to go back. The more its insights become instilled in our institutions the more our everyday experience is sustained by its character. By being embedded in legal principle through a process of incremental increase, the rights, freedoms and immunities that we experience and expect are assured. Therefore, all future laws must rest upon the extent to which our shared identity as a society is manifested in the constitutional and foundational aspects of the rule of law now observed. There must be freedom for the implementation of governmental policy concerning contestable aspects of the rule of law whilst recognising the limits of the constitutional and foundational aspects of the rule of law. For this to occur, the courts as the ultimate arbiters of adherence to those matters must be alive to the distinction.  
There is also a need for the exposition of fundamental legal principle to be poetic. To sustain belief in its importance there must be language that both captures the essential characteristics of the rule of law and inspires adherence to its principles. This can only be done by the expression of ideals that resonate deeply by language suited to the task.
Foundational legal ideas defy expression in the flat cadence of plain English or by the use of the quagmire of modern legal language preoccupied as it is with detail and excessive exposition. Instead, when it comes to the skeleton of principle which holds up the body of the law, there is a need for images to be conjured that ignite in the imagination a conception of what ought to be and the motivation to make it so. Judicial language must have the power to generate the emotional resonance that arises when a decision corresponds with the natural frequency of what is just. 
This is not a call for purple prose. It is a recognition that the rule of law itself finds its best expression when the full capabilities of language are called in aid. So, translated from the original Latin and updated for inclusion, the foundational terms of Chapter 39 of Magna Carta state that no one shall be seized or imprisoned or stripped of their rights or possessions or deprived of their standing in any other way except by the lawful judgment of their equals or by the law of the land. The persistent power in the statement begins with the juxtaposition of the idea of freedom with the possibility that a person may be seized. In the thirteenth century, seisen was a legal term that related to the holding of property or offices. It meant to grip with hands or teeth. The sense of the language is of a forceful taking of liberty as if a person was no more than property.
The same sense is then applied to the rights of a person. Physical form is given to the abstract by describing rights in the same way as possessions that can be taken away. Not just taken, but stripped so that a person is left bare after being plundered of their rights. There is a visceral quality to the language that reflects the idea that a person and their rights are one and the same. 
The terminology excites the understanding that there is something foundational about the rights of a person. Indeed, the language goes on to refer to the standing of a person in the world. This is to refer to those inestimable qualities of status, rank, esteem or existence that are afforded by rights that are recognised by law. It acknowledges the fundamental importance of dignity within any civilised society. 
Finally, there is a description of the only source of authority for such extreme actions, either a person's equals or the law of the land. Significantly absent is any reference to divine or sovereign authority. Instead, a person is to be judged by either their peers or the lex terrae. 
The notion that there is a law of the land to which people are subject is terminology that subsequently found its way into the Supremacy Clause in the United States Constitution. It emphasises the need for a universal character to any law that interferes with basic rights. Such laws must apply to everyone, everywhere in the same way.  But it also captures something deeper: the sense that there is a fundamental character to English law, that it affords due process and has incidents and attributes that mean it is a law to which the people are willing to submit. This is what Brennan J meant by the skeleton of principle that included equality before the law. 
Each legal rule derives its content from the principles upon which the whole system of law stands. Rules conjured by judges at random would be incoherent and unjust. It is those foundational principles of the rule of law that confer authority upon the law to speak. They are the skeleton that holds the body of law together. If they are weakly expressed or clothed in obscurity then they will lack the force that is needed to be heard in the clamour of voices in the public square. 
All this requires clear thinking and ongoing debate around the content of the rule of law and its place in the law's enactment, administration and adjudication. It is not radical departure that is likely. Far more dangerous is the prospect of a gradual weakening over time; a Jenga-like process by which one small piece after another is removed until the whole tower is weakened to the point of collapse. Each compromise may seem insignificant in and of itself but eventually the integrity of the system is lost.  
Finally, I return to my opening remarks concerning identity. The rule of law is a matter of shared identity. It depends upon a conception of the fundamental respect in which we are all equal before the law and that none deserves a privileged place in its administration, especially those who hold power. Unless we begin with a sense of the basic dignity of all then there is no reason to adhere to the rule of law. Unless we understand justice as requiring a kind of universality in the form and content of the law and the way it is administered and adjudicated then we will set off in the wrong direction. We will fail also to deliver the economic fruits of its protections to the whole of society and thereby risk our foundational sense of shared identity.
In consequence, both the exercise of judicial power and the implementation of policy through executive administration of the law by those entrusted with authority to do so must embody a sense that people are not like property or dangerous animals. The law is not imposed unilaterally as if the person to be burdened with its consequences were a disembodied object. It is essential to the rule of law that the majority, particularly those of privilege, claim no special place and that the dignity of each person must be respected. This includes refraining from demands to forgo cultural identity, save to the limited extent that its content is inconsistent with belonging to a society governed by the rule of law.
Today we might gaze upon all that we enjoy by reason of the rule of law and observe that: 'There runs the quick perspective of the future'. We might see in its form and expression an idea so foundational that its power is undeniable. We might also see that its insight and invention is so significant that, if sustained, it has the power to continue to set the course of events.
The words of the title for this address come from Stephen Spender. In the 1930s he observed the march of the national electricity grid across the United Kingdom. Within the grand sweep of its scheme, he saw the potential for electricity to bring a form of social justice to the whole country. He described the architecturally designed pylons as being 'tall with prophecy' and captured the sense in which the country was about to change with these words:
But far above and far as sight endures 
Like whips of anger 
With lightning's danger 
There runs the quick perspective of the future. 
I venture to suggest that the same may be said of the power within the constitutional and foundational aspects of the rule of law. Those pylons too are tall with prophecy. They may be expected to inform the future understanding of the nature and extent of judicial power. As such they foretell our future, they manifest the existence of a shared identity where each is equal before the law, they keep the possibility of dignity for all, but only for so long as we recognise and strive to adhere to them.
This address was delivered on 20 July 2022 in Court 1 of the Old Supreme Court Building, Perth

Schedule
Fundamental rights giving rise to the principle of legality

Freedom of assembly: Melbourne Corporation v Barry (1922) 31 CLR 174
Right to personal liberty: R v Bolton; Ex parte Beane [1987] HCA 12; (1987) 162 CLR 514
Right to a fair trial: Malika Holdings Pty Ltd v Stretton (2001) 204 CLR 290
Legal professional privilege: Daniels Corporation International Pty Ltd v Australian Competition and Consumer Commission [2002] HCA 49; (2002) 213 CLR 543
Right of access to the courts: Plaintiff S157/2002 v Commonwealth [2003] HCA 2; (2003) 211 CLR 476
Right to personal liberty; freedom from being subjected to indefinite or permanent administrative detention: Al-Kateb v Godwin [2004] HCA 37; (2004) 219 CLR 562 
Principles of natural justice: Saeed v Minister for Immigration and Citizenship [2010] HCA 23; (2010) 241 CLR 252
Principle of open justice: Hogan v Hinch [2011] HCA 4; (2011) 243 CLR 506
Protection against double jeopardy: Lacey v Attorney-General (Qld) [2011] HCA 10; (2011) 242 CLR 573
Presumption of innocence: Momcilovic v The Queen [2011] HCA 34; (2011) 245 CLR 1
Freedom of expression: Attorney-General (SA) v Corporation of the City of Adelaide [2013] HCA 3; (2013) 249 CLR 1
Privilege against self-incrimination: Lee v New South Wales Crime Commission [2013] HCA 39; (2013) 251 CLR 196
Protection from compulsory acquisition of property otherwise than on just terms: Attorney-General (NT) v Emmerson [2014] HCA 13; (2014) CLR 393
Freedom from unlawful arrest: North Australian Aboriginal Justice Agency Ltd v Northern Territory [2015] HCA 41; (2015) 256 CLR 569
Right to silence: Strickland v Commonwealth Director of Public Prosecutions [2018] HCA 53; (2018) 266 CLR 325  
See also, the list of fundamental rights identified by Heydon J in Momcilovic v The Queen [2011] HCA 34; (2011) 245 CLR 1 at [444]