The Invisible Constitution in Comparative Perspective

4.4.3.  Implications Extrapolated by Induction

It is sometimes argued that a general principle can be extrapolated from 

particular provisions that collectively give it only partial express protection, 

by a process of induction, and then treated as if it were a freestanding con-

stitutional norm.

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 An American example is in the judgment of Douglas J 

in Griswold v. Connecticut, who notoriously reasoned that the Bill of Rights 

protects a general right to privacy due to the ‘penumbras and emanations’ 

of several express rights that can be regarded as protecting particular aspects 

of privacy.

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 An Australian example is the judgment of Deane and Toohey 

JJ in Leeth v. Commonwealth, who suggested that ‘the existence of a num-

ber of specific provisions which reflect the doctrine of legal equality serves to 

55 

M. Stokes, ‘The Role of Negative Implications in the Interpretation of Commonwealth Leg-

islative Powers’ (2015) 39 Melbourne University Law Review 175, 200. Stokes goes on to make a 

complex and debatable argument that does not reflect current High Court doctrine.

56 

United States Constitution, Article 1, s. 8, cl 18. See John Mikhail, ‘The Constitution and the 

Philosophy of Language: Entailment, Implicature, and Implied Powers’ (2015) 101 Virginia 

Law Review 1063, 1084.

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For discussion of this kind of argument see Mark Walters, ‘Written Constitutions and Unwritten 

Constitutionalism’, in G. Huscroft (ed.), Expounding the Constitution: Essays in Constitutional  

Theory (New York, NY:  Cambridge University Press,  2008)  245,  263; Goldsworthy, chapter 

note, 178–82; W. Sinnott-Armstrong, ‘Two Ways to Derive Implied Constitutional Rights’, in 

J. Goldsworthy and T. Campbell (eds.), Legal Interpretation in Democratic States (Aldershort: 

Ashgate, 2002), 234–8.

58 

Griswold v. Conecticut, 381 U.S. 479 (1965), 484; discussed by Sinnott-Armstrong, Supra note 

57, 234–5.

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The Implicit and the Implied in a Written Constitution 

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make manifest . . . the status of that doctrine as an underlying principle of the 

Constitution as a whole’.

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The suggestion is that, if a number of specific provisions appear to partially 

protect a general principle, that may be evidence that the principle as a whole 

is part of the constitution. Let us assume that this might sometimes be plausi-

ble. The question is how we should understand the nature of such inductive 

arguments, and of the implications they are used to reveal. Inductive argu-

ments are inferences to the best explanation of some observed phenomena: 

they seek to explain the observed in terms of the unobserved. When used 

in science, for example, an inductive argument might take some observed 

regularities to be evidence of an underlying causal relationship that can be 

expressed by a general physical law. In the legal context, what is the nature of 

this unobserved (unexpressed) thing, which is the counterpart of the physical 

law? Legal provisions are the products not of mindless causal processes gov-

erned by general physical laws, but of intentional human action. The legal 

equivalent of the physical law revealed by scientific induction is therefore the 

lawmaker’s intention or purpose.

It follows that an inductive argument is persuasive only if particular provi-

sions that selectively instantiate some general principle are evidence that the 

framers intended the principle itself, and not just the particular provisions, to 

be judicially enforceable. An implication is justified when there is sufficient 

evidence of the existence of such an intention. The catch, of course, is that if 

this is what the inductive argument points to, then other evidence that such 

an intention could not have existed will defeat the argument. Inductive argu-

ments are defeasible, not conclusive: although they may include evidence of 

an implication, they can be defeated by stronger counter-evidence.

A comprehensive review of the evidence will often reveal that the framers 

intended to pursue some general purpose, or implement some general prin-

ciple, only by particular means and to a limited extent. As Terrance Sandalow 

pointed out,

By wrenching the framers’ ‘larger purposes’ from the particular judgments 

that revealed them, we incur a loss of perspective, a perspective that might 

better enable us to see that the particular judgments they made were not 

imperfect expressions of a larger purpose but a particular accommodation 

of competing purposes. In freeing ourselves from those judgments we are 

not serving larger ends determined by the framers but making room for the 

introduction of contemporary values.

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