Illogical and Irrational Decisions - Confirmed as a Ground of Judicial Review for Decision-Makers

Key Points:

An administrative decision can now be reviewed on the basis that no rational or logical decision-maker could arrive at the decision on the same evidence.

The High Court has recently confirmed the availability of aground of judicial review that focuses on illogical and irrational reasoning processes (Minister for Immigration and Citizenship v SZMDS [2010] HCA 16).

This means that it is clear that an administrative decision can now be reviewed on the basis that no rational or logical decision-maker could arrive at the decision on the same evidence.

Is illogical and irrational reasoning a ground of review?

The possibility of reviewing administrative decisions on the basis of illogical and irrational reasoning had been flagged by the High Court in Applicant S20/2002 (2003) 77 ALJR 1165 and SGLB (2004) 78 ALJR 992.

Following these decisions, uncertainty had arisen in the Federal Court over whether illogicality or irrationality was a free-standing ground of review. SZMDS dispels that uncertainty in the High Court's most thorough examination of the scope of this ground of review.

While SZMDS does confirm the availability of illogicality and irrationality as a ground of review, the judgments of Acting Chief Justice Gummow and Justice Kiefel, and Justices Crennan and Bell do not present a uniform approach to the meaning and scope of illogicality and irrationality. We have limited our consideration of those concepts to the judgment of Justices Crennan and Bell, as that judgment provides a more detailed discussion than that of Acting Chief Justice Gummow and Justice Kiefel.

Describing a decision as illogical or irrational is often merely a way of expressing disagreement with it, in the sense that...