On equating ‘mays’ with ‘musts’: When can a discretionary power be interpreted as a mandatory one?

• Author: Draga, L.
• DOI: https://doi.org/10.47348/SALJ/v138/i3a9
• Published date: 09 September 2021
• Date: 09 September 2021
• Citation: (2021) 138 SALJ 649
• Pages: 649-681

649

ON EQUATING ‘MAYS’ WITH ‘MUSTS’:

WHEN CAN A DISCRETIONARY POWER BE

INTERPRETED AS A MANDATORY ONE?

LISA DRAGA†

Lecturer, School of Law, University of the Western Cape

In this articl e I investigate when the other wise permissi ve term ‘may’ in an empow ering

provision can be interpreted as imposing a duty on the recipient of that power to act.

In the rst part, I examine our courts’ pre-democratic approach to answering this

question through an analysis of pre-democratic judgments. In particular, I scrutinise

certain factors that the courts have traditionally relied on in this regard. Thereafter,

I consider the present-day rules of statutory interpretation and its application to

the may/must question. Next, I analyse the Constitutional Court’s approach to

determining w hen the use of ‘may’ to confer a pow er through statute can be inter preted

as requiring th e power be exercised. I underta ke an analysis of a dissection of releva nt

Constitutional Court judgments. These judgments are dissected for purposes of

illustrating the cont inued relevance of the traditional fac tors that were employed before

democracy. Finally, I focus on th e may/must question in the ty pical public-law conte xt

of this interpretative exercise. I examine potential grounds of revie w where the holder

of the power has failed or refused to execute a duty attached to permissive language.

I also consider separation-of-powers concerns that may likely arise.

Discretion – permis sive – mandatory – power

I INTRODUCTION

Law school teaches that the statutory use of the word ‘may’ can be

interprete d, in a given context, as ‘must’ and t hat ‘must’ can be interprete d,

in tur n, as ‘may’. Also taught is the de fault position that , absent a compellin g

context to the contrary, a ‘must’ ordinarily imputes a ‘must’ and a ‘may’

ordinar ily imputes a ‘may’.1 However, for ‘as long as the English language

retain s its meaning “may” can never be equ ivalent to “must”’.2 It would be

nonsensical to advocate otherwise.3 The question that then presents itself

is when can a may be interpreted as a must? In other words, when can the

ostensibly permissive term ‘may’ be interpreted as mandatory?

Our courts are confronted with this question in situations where

obligations are created or powers bestowed through apparently dis cre-

tionar y language i n a legal provision and t he court must determ ine whether

† LLB (Western Cape) LLM (University of Missouri, Columbia). ht t p s :// o r c id .

org/0000-0002-8456-3112. Thank s go to Sarah Fick, Wessel le Roux and Kessler

Perumalsamy for their contribut ions to this article.

1 Cora Hoexter Administrative Law in South Africa (2007) 47; J R de Ville

Constitutional and Statutory Inter pretation (2000) 260.

2Schwartz v Schwartz1984 (4) SA 467 (A) at 474C–D, referring to Noble &

Barbour v South African Railways and Harbours 1922 AD 527 at 540.

3 R v Dietrich 1946 EDL 57 at 61–2.

https://doi.org/10.47348/SALJ/v138/i3a9

(2021) 138 SALJ 649

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650(2021) 138 THE SOU TH AFRICAN LAW JOUR NAL

https://doi.org/10.47348/SALJ/v138/i3a9

the holder of the power is mandated to exercise that power.4 This article

is aimed, rst, at exploring the pre-constitutional approach to answering

the above question through an analysis of relevant pre-democratic case

law. I distil and discuss certain factors that the courts have traditionally

relied upon to reach either a mandatory or a discretionary meaning.

The present-day rules of statutory interpretation and its application to the

may/must question are thereafter examined.

Next, the article scrutinises the Constitutional Court’s approach to

determining whether an ostensibly permissive empowering provision

can be read as mandatory. This is undertaken through an exposition of

the most relevant Constitutional Court cases. These cases are analysed

for purposes of determining to what extent the Constitutional Court has

referred to and applied the traditional (pre-constitutional) factors when

deciding this issue. Through this analysis this article seeks to determine

whether the court, although not explicitly, has nonetheless assimilated

some of the traditional factors into its interpretative approach. This

article speculates to what extent, if any, courts may rely on the traditional

factors when ruling on future cases. Finally, this article focuses on the

may/must question in the typical public-law context of this interpretative

process. It considers potential grounds of review under the Promotion of

Administrative Justice Act (‘PAJA’)5 for a power-bearer’s failure or refusal

to execute a duty attached to permissive language. A potential review

stemming from the breach of the principle of legality is also considered.

Finally, separation-of-powers concerns are discussed.

II THE PRE-DEMOCRATIC STANCE ON ‘MAYS’ AND

‘MUSTS’

Due to the diering dominant theories of interpretation at times in

our legal history, the inquiry as to when a may can be interpreted as a

must in the context of an empowering provision is era dependant. In the

pre-constitutional age, an answer to this question would have necessitated

4 Courts have also engaged with the question whether a ‘must’ can be

interpreted as a ‘may’ where procedural requirements for the performance

of an act have been statutorily set and the court is required to determine the

consequences of a lack of compliance. Here the court must label the provision

peremptory (full compliance needed) or directory (substantial compliance will

suce). See Christo Botha Statutory Interpretation: An Introduction for Students

4 ed (2005) 109; G E Devenish Interpretation of Statutes 2 ed (1996) 223; L M du

Plessis The Interpretation of Statutes (1986) 143; F J van Heerden & A C Crosby

Interpretation of Statutes (1996) 75. Schola rs have tended to xate on th is question,

and have neglected the question regarding when a ‘may’ can be interpreted as a

‘must’ in the context of an empowering provision: see Botha op cit at 109–13;

Devenish op cit at223–35; Du Plessis op cit at 143–7; Van Heerden & Crosby

op cit at 75–8.

5 Act 3 of 2000.

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ON EQUATING ‘MAYS’ WIT H ‘MUSTS’ 651

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a discussion of the Golden Rule of interpretation. Also essential to

that discussion would be the courts’ repeated and extensive reliance

on Julius v Bishop of Oxford (‘Julius’).6 The part below focuses on the

pre-democratic jurisprudential method of determining whether an

ostensibly permissive empowering provision carried an attendant

obligation on the power-holder to act.

(a) The Golden Rule

The Golden Rule is aimed at establishing legislative intent through

examining the language of the text.7 Where words are clear and

unambiguous, the clear meaning must prevail.8 Under the rule, courts

looked beyond the grammatical meaning if that meaning would lead to

absurd results or if the provision permitted ambiguity.9 A court would

not, without cogent reasons, depart from the ordinary meaning attached

to ‘may’.10 A deviation could occur to give eect to the manifest intent

of the legislature.11 The onus was on whichever of the litigants sought a

mandator y interpretation to prove th at this interpret ation was warranted .12

The courts m ade clear that no univer sal rule could be la id out as to when

a ‘may’ could be read as a ‘must’.13 Where courts explored words beyond

their gra mmatical mea ning, they made use of va rious techniques to cla ssify

‘may’ as discretionary or obligatory. This included the use of common-

law presumptions of statutory interpretation. These presumptions served

as principles that aided courts when construing legislation.14 Courts

were even prepared to consider extraneous factors to determine if a

mandatory meaning applied.15 Whether a section contained guidelines as

6 (1880) 5 AC 214.

7 De Ville op cit note 1 at 94.

8 Ibid.

9 W le Roux ‘Directory provisions, section 39(2) of the Constitution and the

ontology of statutory l aw: African Christian Democratic Party v Electoral Commission

2006 (3) SA 305 (CC)’ (2006) 21 SA Public L aw 382.

10 African Commercial and Distributive Workers’ Union v Schoeman, NO & another

1951 (4) SA 266 (T) at 274.

11Amalgamated Packaging Industries Ltd v Hutt & another1975 (4) SA 943 (A)

at 950D.

12Hartley NO v T he Master 1921 AD 403 at 407–8; Blo emfontein Town Council v

Bloemfontei n Licence Certi cate Board & another 1927 OPD 19 at 21–2; R v Zock 192 8

AD 384 at 389; Lyn ch v Union Government (Min ister of Justice) 1929 AD 281 at 284;

Desai v Wessels and Torlage & another 1964 (1) SA 783 (D) at 787.

13 Custodian of Enemy Property v Brakpan Mines, Ltd 1922 TPD 179 at 188;

Rex v Dietrich supra note 3 at 62.

14Annie Singh ‘A re-evaluation of the common-law presumptions of inter-

pretation in the light of the Constitution’ (2012) 75 THRHR at 79 and De Ville

op cit note 1 at 164.

15Chief Pass Ocer, Johannesburg v Mashamba1917 AD 397 at 404; Groenewald

v Minister of Fina nce 1927 TPD 679 at 690; Minister of Defen ce v Bourke 1950 (1) SA

393 (A) at 397; Hall v Military Pensions Appeal Tribunal 1963 (3) SA 407 ( T).

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