Robert Alexy and the Dual Nature of Law

• Published date: 01 June 2020
• Date: 01 June 2020
• Author: Torben Spaak
• DOI: http://doi.org/10.1111/raju.12285

© (2020) John Wiley & Sons Ltd.

Ratio Juris. Vol. 33 No. 2 June 2020 (150–168)

Robert Alexy and the Dual Nature

of Law

TORBEN SPAAK*

Abstract. Robert Alexy’s claim that law of necessity has a dual nature raises many interesting

philosophical questions. In this article, I consider some of these questions, such as what the

meaning of the correctness thesis is, whether Alexy’s discourse theory supports this thesis, and

whether the thesis is defensible; whether Alexy’s argument from anarchy and civil war sup-

ports the claim that law of necessity has a real dimension; and what the implications are of the

use of moral arguments, such as the argument from injustice, for the status of Alexy’s inquiry.

1. Introduction

Robert Alexy maintains that law has a dual nature, in the sense that it necessarily has

both a real and an ideal dimension, and that this feature is “the single most essen-

tial feature of law” (Alexy 2010, 180). He explains that the elements of authoritative

issuance and social efficacy constitute the real dimension of law, whereas the claim

to moral correctness makes up the ideal dimension. And, he points out, the dual-

nature thesis implies nonpositivism: “If one claims that social facts alone can deter-

mine what is and what is not required by law, that amounts to the endorsement of

a positivistic concept of law. Once moral correctness is added as a necessary third

element, the picture changes fundamentally. A non-positivistic concept of law

emerges” (ibid., 167).

The dual-nature thesis raises many interesting philosophical questions, but I shall

be content to consider just a few of them in this article. I shall consider (i) the meaning

and defensibility of the correctness thesis, which has it that law of necessity raises a

claim to moral correctness; (ii) the question of whether Alexy’s discourse theory—

according to which some legal claims, say, “p is obligatory,” are neither discursively

* Professor of jurisprudence, Department of Law, Stockholm University. I would like to thank

the participants in the advanced seminar in practical philosophy, Uppsala University, especially

Victor Moberger, for helpful comments on the article. I would also like to thank Christoph

Bezemek, Åke Frändberg, and Karl Pettersson for helpful comments on various versions of the

article, and Robert Alexy and the participants in the workshop Law in Quest of Its Promise:

Discussing Professor Robert Alexy’s Legal Theory at the Tallinn University School of Governance,

Law, and Society for helpful comments on my presentation of the main ideas in this article. In

addition, I would like to thank an anonymous reviewer for identifying difficulties in the text

and for suggesting improvements. Last but not least, I would like to thank Robert Carroll for

checking my English. As always, the author alone is responsible for any remaining mistakes

and imperfections.

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Ratio Juris, Vol. 33, No. 2 © (2020) John Wiley & Sons Ltd.

Alexy and the Dual Nature of Law

necessary, nor discursively impossible, but are instead discursively possible, or, as I

would say, discursively contingent—really supports the correctness thesis and, more

generally, the claims of normative necessity that are involved in the analysis of the

concept of law put forward by Alexy; (iii) the validity of the argument from anarchy

and civil war, which Alexy adduces in support of his claim that law of necessity has

a real dimension; and (iv) the implications for the status of Alexy’s inquiry into the

use of moral arguments—specifically, the argument from injustice—in this inquiry.

I am going to argue (A) that Alexy’s correctness thesis is defensible, and that

Joseph Raz’s well-known objection—that the correctness thesis is merely a special

case of a more general, conceptual thesis about intentional actions—does not under-

mine Alexy’s inquiry into the nature of law; (B) that Alexy’s discourse theory can

indeed support the correctness thesis and the claims of normative necessity that are

involved in the analysis of the concept of law put forward by Alexy;1 (C) that the ar-

gument from anarchy and civil war fails to establish the desired conclusion, that law

of necessity has a real dimension; and (D) that Alexy’s use of moral arguments in the

analysis is incompatible not only with the view that Alexy is analyzing the concept of

law, but also with the view that he is explicating (or rationally reconstructing) said

concept.

I shall begin with a brief consideration of Alexy’s thoughts on the debate about

the concept of law and of the conceptual framework within which Alexy considers

this debate (Sections 2–3). I then proceed to consider the correctness thesis and the

correctness argument (Section 4) and Raz’s above-mentioned objection to the cor-

rectness thesis (Section 5). Next, I consider, first, the above-mentioned problem of

discursive possibility (Section 6), and then the claim that law of necessity has a real

dimension and, in particular, Alexy’s argument from anarchy and civil war in sup-

port of this claim (Section 7). The article concludes with a consideration of whether

Alexy’s inquiry into the nature of law is best seen not as an analysis of the concept

of law, but as an explication of this concept, and of the permissibility of moral argu-

ments in this inquiry (Section 8).

2. The Debate about the Concept of Law

The inquiry into the nature of law is usually (see, e.g., Hart 1961; Raz 2009), but not

always (see, e.g., Moore 2000), conceived as an analysis of the concept of law. This is

also Alexy’s view. The task of the legal philosopher, Alexy explains, is to analyze the

concept of law; and if the analysis is successful, the analyst has thereby clarified the

nature of law. The relevance of conceptual analysis to the question of law’s nature,

he explains, is due to the fact that concepts necessarily have not only a conventional,

but also an ideal dimension:

As products of a culture, concepts are socially established rules that concern the meaning of

words. To this extent, concepts have a conventional character. They are conventional rules of

meaning. But concepts [...] are conventions of a special kind. They claim, as Kant puts it, to be

“adequate to the object” [...]. In this way, they are intrinsically related to the correctness or truth

1 The term discursive possibilityis not ideal, because in any system of modal logic “necessary A”

entails “possible A” (□A → ◊A) but contradicts “possible -A (◊-A).” The problem, then, is that,

on Alexy’s analysis, contrary to what the reader is likely to assume, discursive necessity does

not entail discursive possibility but contradicts it.