Skip to main content
Glite Dictionary
ratio decidendi

ratio decidendi

9.9
A rule or reason in a court decision that later courts must follow
  • noun
  • /ˈreɪʃioʊ dɪˈsɪdɛndi/
  • Formal
translation icon : ratio decidendi
  • The judge explained the ratio decidendi of the case, which set a crucial precedent for future rulings.

Examples

  • Understanding the ratio decidendi helps lawyers argue their cases based on established legal principles.

  • But the inability to pick out a single opinion from the plurality case as reflecting the controlling ratio does not render the ratio decidendi approach to precedent unworkable.

    Academic text (2017)

  • This article proposes a revised approach to plurality precedent that builds from the ratio decidendi model's core premise: namely, that the precedential effect of a judicial decision should be determined by reference to the deciding court's reasons for judgment.

    Academic text (2017)

  • The article analyzed the ratio decidendi in landmark decisions that shaped contemporary law.

Antonyms

to overturn
  • Formal
122 5.6

Officially cancel a decision or law

Surface Forms

ratio decidendi singular
ratio decidendis plural

Morphology

ratio + decidendi

This is a Latin legal term rather than a normal English compositional phrase; the provided constituent words are not standard English dictionary entries and a B1 learner would not reliably recognize their meanings. Even though etymologically it literally means something like 'the reason for deciding', the phrase is specialized legal jargon whose specific sense as the binding principle of a judgment is not predictable to general learners.

Etymology

Ratio decidendi comes from Latin: ratio means 'reason' and decidendi means 'of deciding'. It refers to the judge's real reason for a decision, and that reason becomes the rule other courts follow, so the phrase means the legal principle that guides later cases.