Brennan v HM Advocate 1977 JC 38 was a Scots criminal appeal case decided in the High Court of Justiciary in its capacity as the Court of Criminal Appeal. The case set the precedent that voluntary intoxication, whether by drink or drugs, cannot be used to establish defences of automatism or insanity. Brennan had been convicted of murdering his father during a state of intoxication. This was held not to qualify as automatism as the appelant had entered this state voluntarily. The Court-based this reasoning on a number of passages from the work of Baron Hume, one of the institutional writers.