In Canada, as in other jurisdictions, natural justice has included in the injunction that, ‘No one may be the judge in his or her own cause’. This rule began with a concern for self-dealing and pecuniary interests, but has evolved to include a range of biases, including attitudinal ones.

The essence of bias is a closed mind, or put differently, the absence of an open mind – as one judge observed: ‘bias represents a predisposition to decide an issue or cause in a certain way which does not leave the judicial mind perfectly open to conviction’.