"The rule against bias is one thing. The right to be heard is another. Those two rules are the essential characteristics of what is often called natural justice. They are the twin pillars supporting it.
They have recently been put in the two words, Impartiality and Fairness. But they are separate concepts, and they are governed by separate considerations.
If the right to be heard is to be a real right which is worth anything, it must carry with it a right in the accused man to know the case which is made against him; and then he must be given a fair opportunity to correct or contradict them ...
It follows, of course, that the judge or whoever has to adjudicate must not hear evidence or receive representations from one side behind the back of the other. The court will not inquire whether the evidence or representations will work to his prejudice. Sufficient that they might do so. The Court will not go into the likelihood of prejudice. The risk of it is enough. No one who has lost a case will believe he has been fairly treated if the other side has had access to the judge without his knowing."4