natural justice is an expression of English Common Law. Natural justice is not a single theory it is a family of views. In one sense administering justice itself is treated as natural virtue and, therefore, a part of natural justice. It is also called naturalist approach to the phrase natural justice and is related to moral naturalism . Moral naturalism captures the essence of commonsense morality that good and evil, right and wrong, are the real features of the natural world that human reason can comprehend. In this sense, it may comprehend virtue ethics and virtue jurisprudence in relation to justice as all these are attributes of natural justice. We are not addressing ourselves with this connotation of natural justice here.
In Common Law, the concept and doctrine of natural justice, particularly which is made applicable in the decision-making by judicial and quasi-judicial bodies, has assumed a different connotation. It is developed with this fundamental in mind that those whose duty is to decide, must act judicially. They must deal with the question referred both without bias and they must give (sic an opportunity) to each of the parties to adequately present the case made. It is perceived that the practice of aforesaid attributes in mind only would lead to doing justice. Since these attributes are treated as natural or fundamental, it is known as natural justice . The principles of natural justice developed over a period of time and which is still in vogue and valid even today are: (i) rule against bias i.e. nemo debet esse judex in propria sua causa; and (ii) opportunity of being heard to the party concerned i.e. audi alteram partem. These are known as principles of natural justice. To these principles a third principle is added, which is of recent origin. It is the duty to give reasons in support of decision, namely, passing of a reasoned order .
Dharam Pal Satya Pal Limited v. Deputy Commissioner Central Excise Guhati and others, (2015) 8 SCC 519