Re Judiciary and Navigation Acts (1921) 29 CLR 257 is a landmark judgment of the High Court of Australia. The matter related to what is a legal matter and the High Court's ability to issue opinion outside a case.
The Attorney-General of Victoria, raised an objection that section 88 of the Judiciary Act 1903 was beyond the powers of the Commonwealth Parliament.
The court found that the High Court could not issue legal opinions unattached to a specific case. The joint majority judgment stated:
On the issue of what constituted a matter they said: