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3.5.1 Introduction

By Tatiana Duarte

Reasoning and interpretation may take place in various contexts, as virtually anyone able to read may interpret law or have an opinion about the outcome of a case. In this contribution, legal reasoning and interpretation are understood as authoritative practices of the judiciary when deciding legal cases.

Legal reasoning and interpretation are mutually-constitutive practices

Legal reasoning and interpretation are different, although mutually constitutive, practices of the judicial activity. Their separate treatment is a (de)construction which is possible only by rationalising them as (mere) intellectual operations. The objective of such separation is highlighting their different outlines and the expectations each of them generates.

For the purposes of this contribution, we define legal reasoning and interpretation as follows.

  • Legal reasoning concerns the intellectual trail that connects a set of facts to the legal system in such a way that the latter is understood as ruling the former. 1
  • Whereas interpretation corresponds to the attribution of authoritative meaning to legal norms through facts and to facts through legal norms, according to interpretative practices acknowledged as such by an interpretative community. 2

However, we must keep in mind that, as authoritative practices, they overlap, as legal reasoning implies interpretation as much as interpretation implies legal reasoning. Their mutually constitutive character will be evident in some sections of this contribution, particularly where their practical aspects are approached.


  1. Some authors distinguish legal argumentation from legal reasoning, the former being the theory which studies the conditions for a satisfactory justification of judicial decisions, the latter, the one which studies how the individual decision derives from pure normative statements. This distinction may be found in F. Atria, On Law and Legal Reasoning (Hart Publishing 2001) p. 175, n. 10. This conceptual separation may be perceived as implying two different moments in the judiciary practice: (i) legal reasoning, i.e., a procedure or a form that allows deriving individuals (decisions) from universals (legal norms); (ii) legal argumentation, i.e., a substantive moment where the interpretative content and the relations between the norms of the legal system (either material, hierarchical, logical, systematic, etc.), as the relations between the legal system and the facts, allow the attribution of legal effect through an iteration between ought and is. Although it could seem that this distinction has some resonance in our contribution, reborn under the names of legal reasoning and interpretation, that is not the case. Logical inference neither exhausts, nor is exclusive of the process legal reasoning. Atria acknowledges that the referred distinction does not hold when legal reasoning is perceived as being dependent upon argumentation. Indeed, this work assumes the artificiality of the separation between legal reasoning and interpretation. 

  2. For the concept of interpretative community, see the section ‘modes of existence’, under the concept of ‘legal reasoning’. 

This page was last updated on 14 July 2021.