Legal Dictionary of Pakistan

ratio decidendi

n. [Latin "the reason for deciding"] 1. The principle or rule of law on which a court's decision is founded <many poorly written judicial opinions do not contain a clearly ascertainable ratio decidendi>. 2. The rule of law on which a later court thinks that a previous court founded its decision; a general rule without which a case must have been decided otherwise <this opinion recognizes the Supreme Court's ratio decidendi in the school desegregation cases>. -Often shortened to ratio. Pl.