The Invisible Constitution in Comparative Perspective

Wik Peoples v. Queensland (1996) 187 CLR 1, 179–80.

17 

As opposed to being the choices of individual judges who then impose their wills upon their 

fellow judges in disregard of the social practice that constitutes the rule of recognition.

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152 

Patrick Emerton

On the ‘thick’ picture of validation, what it is that is validated are the various 

rules and principles that make up the legal system and determine outcomes 

and consequences within it. In a legal system of even modest complex-

ity, these will include rules and principles that have not been expressly or 

self-evidently stated by any authoritative source, but rather are derived – as 

implications, consequences, interpretations and the like – from those sources. 

Call this unexpressed law (which contrasts with expressed law). There also are 

likely to be rules and principles for generating unexpressed law (e.g., rules for 

reconciling or integrating prima facie conflicting sources; rules of statutory 

interpretation; rules for deriving authoritative principles from decided cases; 

etc.), without which no account can be given of how the unexpressed law is 

part of the system.

18

 Call these rules of legal inference.

19

 On the ‘thick’ Hartian 

conception of law, the rules of legal inference themselves stand in need of 

validation, if they are to be part of the system.

It might be tempting to think that the rules of legal inference could them-

selves be part (perhaps the major part) of the rule of recognition. However, 

Dworkin has advanced a very persuasive argument that these sorts of rules are 

simply not apt to be exemplified as social rules or practices:

20

 rules having this 

sort of complexity, and hence apt to generate disagreement around their inter-

pretation and application, will simply not generate the convergent behaviour 

that is characteristic of a social rule.

In any event, there is good reason to think that these rules of legal inference 

could not be written law and hence either: (a) if part of the rule of recogni-

tion would render it impossible to (fully) declare that rule in writing; or (b) if 

18 

On some occasions (e.g., if in the context of an exposition of some point by a court with appro-

priate standing in a judicial hierarchy), the ascertainment of unexpressed law may render the 

hitherto-unexpressed expressed.

19 

It is beyond the scope of this chapter to consider in any detail the possible content of rules 

of legal inferences, which obviously can vary extremely widely across different legal systems. 

Within the Australian legal system, one important class of such rules is that of rules which 

determine the consequence for one expressed law of changes in another expressed law that 

do not directly refer to the first expressed law. One example of such a rule is the principle of 

legality, which determines the consequences for various expressed rules of the common law 

of the enactment of a statute that does not expressly address those common law rules but on 

its face may bear upon them (see e.g., Lacey v. Attorney-General (Qld) (2011) 242 CLR 57). A 

second (which has no special name) is the rule used by the High Court in PGA v. The Queen 

(2012) 245 CLR 355 to determine the consequence of various express laws that changed the 

legal status of women (e.g., emancipation statutes; divorce statutes; enfranchisement statutes, 

etc.) for the common law rule governing the possibility of rape in marriage: for the majority’s 

statement of the rule, see (2012) 245 CLR 355, 373 [30] (French CJ, Gummow, Hayne, Cren-

nan and Kiefel JJ).

20 

Ronald Dworkin, ‘The Model of Rules II’, in Taking Rights Seriously (Cambridge: Harvard 

University Press, 1978), 54–7, 61–3.

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