Explain in brief doctrine of 'Nemo Judex in Causa Sua'.

Nemo Judex in Causa Sua is Rule against bias. According to this rule no person should be made a judge in his own cause. Bias means an operative prejudice whether conscious or unconscious in relation to a party or issue. It is a presumption that a person cannot take an objective decision in a case in which he has an interest. The rule against bias has two main aspects- one, that the judge must not have any direct personal stake in the matter at hand and two, there must not be any real likelihood of bias. Bias can be of the following three types: Pecuniary bias: The judicial approach is unanimous on the point that any financial interest of the adjudicatory authority in the matter, howsoever small, would vitiate the adjudication. Thus a pecuniary interest, howsoever insufficient, will disqualify a person from acting as a Judge. Personal bias: There are number of situations which may create a personal bias in the Judge's mind against one party in dispute before him. He may be friend of the party, or related to him through family, professional or business ties. The judge might also be hostile to one of the parties to a case. All these situations create bias either in favour of or against the party and will operate as a disqualification for a person to act as a Judge. Subject matter bias: A judge may have a bias in the subject matter, which means that he himself is a party, or has some direct connection with the litigation. To disqualify on the ground of bias there must be intimate and direct connection between adjudicator and the issues in dispute. To vitiate the decision on the ground of bias as for the subject matter there must be real likelihood of bias.