No one ought to be judge in his own cause.
The rule in this maxim is inflexible, and as well the king as the commoner is subjected to it ; and some few cases have arisen in which it has been so adjudged.
The manifest injustice of a man being judge in his own cause will not be denied, and that being so, it may be supposed that such a case is of rare occurrence, and, indeed, so it is ; for it is only indirectly that such a case occurs ; as, for instance, where a judge interested, as shareholder or otherwise, in some railway or other company or undertaking, having a suit before him, proceeds to hear the cause and adjudicate. To such a case, namely, that in which he has an interest merely, though he be not a party to the suit, the rule applies.
The maxim applies to all judges alike, whether superior or inferior. The following is an important and apt instance : —
Where a company filed a bill against a landowner and obtained a decree in their favour, which was sought to“ be set aside on appeal before the Lord Chancellor, who was a shareholder in the company ; that fact being unknown to the defendant ; and the Lord Chancellor affirmed the decree : the House of Lords reversed the decree of the Lord Chancellor solely on the principle of this maxim. And it was there stated that it was of the greatest importance that the maxim, ” No man shall be judge in his own cause,“ be observed ; and that the rule was intended to. apply not merely where he was a party, but where he had any interest. It was there also observed, that the House of Lords had again and again set aside proceedings of inferior tribunals because an individual who had an interest in the cause took part in the decision ; and that that case against the Lord Chancellor would be a good example and a lesson to all inferior tribunals in time to come, not only that in their decrees they are not to be influenced by their personal interest, but that they ought to avoid the appearance even of being influenced by such interest.
Again, where by a building contract it was stipulated that the work was to be done to the satisfaction of the defendant himself ; it was held that his approval of the work done was not a condition precedent to payment, for that would make him judge in his own cause. So, also, a justice of the peace interested in a matter brought before him cannot hear it or adjudicate upon it, or take part with other justices in so doing ; and objections on this ground are of daily occurrence. And where, upon an appeal by a water company against an assessment to a poor-rate, the presiding judge, the deputy recorder, reduced the rate and gave costs to the appellants, and it afterwards appeared that the deputy recorder was, at the time of the trial of the appeal, the registered shareholder of five shares in the company, though he was at the time under a contract to dispose of them, and, as he swore, believed he had no beneficial interest whatever in the company ; it was held that he was, notwithstanding, an interested party, and incompetent to try the appeal.
The maxims, “Nemo potest esse simul actor et judex” — No one can be at the same time judge and party ; - Aliquis non debet esse judex in propria causa,, quia non potest esse judex et pars” — No man ought to be judge in his own cause, because he cannot be judge and party, are further instances of the application of the same rule.