Doctrine of severability
Article 13 of the constitution says that a law is void if it is inconsistent with the Fundamental Rights. A void statute is devoid of any legal force and courts take no notice of such a statute. The same article makes clear that in future, the State shall not make any law which takes away the Fundamental Rights given by Part III. The law here does not only include the legislation but also an ordinance, order, bye-law, rule, regulation, notification. This means that state cannot make any law which takes away the fundamental rights of the individuals.
Importance of article 13 is that it has provided basis for judicial review of all legislations in India, past as well as future. All laws whether made by a legislature or by a delegated authority and all executive acts must respect and conform to the fundamental rights. The ordinances promulgated by the president under art.123 or by the governor under art. 213 must also not be inconsistent with the implement the fundamental rights. Article 13 impose an obligation on the state to respect and implement the fundamental rights and at the same time confers a power on the courts to declare a law/act void if it infringes a fundamental right. Art.13, thus, provides teeth to the fundamental rights and makes them justifiable i.e. enforceable in the courts.
However, the article also says that a law is void only “to the extent of the inconsistency or contravention” with the relevant Fundamental Right. This implies that an act may not be void as a whole but only a part of it may be void and if that part is severable from the rest which is valid, and then the rest may continue to stand and remain operative. This is called “Doctrine of Severability.” The Act will then be read as if the invalid portion was not there. If, however, it is not possible to separate the valid from the invalid portion, then the whole of the statute will have to go.