UPSC Notes / Polity & Constitution / Chapter 17
Chapter 17 of 20

Constitutional Doctrines and Landmark Judgments

Doctrines used by courts to interpret the Constitution — Basic Structure, Pith and Substance, Severability, Colourable Legislation — with a landmark-case ready-reckoner.

📖 ~15 min read ⚖️ Polity & Constitution

Introduction

Courts have developed several interpretive doctrines to resolve constitutional disputes — particularly over the validity of laws and the boundary between Union and State powers. These doctrines, alongside a set of landmark judgments, are a high-yield, frequently-tested area for both Prelims and Mains.

Key Constitutional Doctrines

DoctrineMeaning
Basic StructureParliament cannot amend the Constitution so as to destroy its foundational features (Kesavananda Bharati, 1973)
Doctrine of SeverabilityOnly the unconstitutional part of a law is struck down if it can be separated from the valid part; the whole law falls only if inseparable
Doctrine of EclipseA pre-Constitution law inconsistent with Fundamental Rights is not dead but "eclipsed" — it becomes operative again if the relevant FR is amended to remove the inconsistency
Doctrine of Pith and SubstanceTo decide which legislative list a law truly falls under, courts look at its "true nature and character," not incidental encroachments into another list
Doctrine of Colourable Legislation"What cannot be done directly cannot be done indirectly" — a legislature cannot do indirectly what it lacks the power to do directly
Doctrine of RepugnancyGoverns conflict between a Central and State law on a Concurrent List subject (Article 254) — Central law prevails unless the State law has Presidential assent
Doctrine of Harmonious ConstructionWhen two provisions of law seem to conflict, courts interpret them so both can operate together, rather than treating one as overriding
Doctrine of Territorial NexusA state law can have extra-territorial operation if there is a sufficient nexus between the state and the subject-matter of the law

Landmark Judgments — Ready Reckoner

CaseYearKey Holding
Kesavananda Bharati v. State of Kerala1973Propounded the Basic Structure doctrine
Maneka Gandhi v. Union of India1978Expanded Article 21 — "procedure established by law" must be fair, just, and reasonable; linked Art. 14, 19, and 21
Minerva Mills v. Union of India1980Struck down absolute primacy of DPSPs over FRs; judicial review is part of Basic Structure
S.R. Bommai v. Union of India1994Federalism is part of Basic Structure; laid safeguards against misuse of Article 356 (floor test requirement)
Indra Sawhney v. Union of India ("Mandal case")1992Upheld 27% OBC reservation; capped total reservation at 50% (with exceptions); introduced the "creamy layer" concept
Vishaka v. State of Rajasthan1997Laid down guidelines against sexual harassment at the workplace (later codified in the POSH Act, 2013)
Kihoto Hollohan v. Zachillhu1992Upheld the Tenth Schedule; Speaker's decision on defection is subject to judicial review
I.R. Coelho v. State of Tamil Nadu2007Ninth Schedule laws enacted after 24 April 1973 are subject to Basic Structure review
Justice K.S. Puttaswamy v. Union of India ("Right to Privacy case")2017Declared the Right to Privacy a Fundamental Right under Article 21 (9-judge bench, unanimous)
Navtej Singh Johar v. Union of India2018Decriminalised consensual homosexual acts by reading down Section 377 IPC
Justice K.S. Puttaswamy (Aadhaar case)2018Upheld the constitutional validity of Aadhaar with certain restrictions; held it could not be introduced as a Money Bill for all purposes (later revisited)
Supreme Court Advocates-on-Record Assn. v. Union of India (NJAC case)2015Struck down the National Judicial Appointments Commission; restored the Collegium system
Anoop Baranwal v. Union of India2023Directed a selection committee (PM, Leader of Opposition, CJI) for appointing Election Commissioners, pending a law by Parliament — later superseded by the 2023 ECI Appointment Act
💡 Exam Tip: For Mains, always link the doctrine/case to its constitutional consequence — e.g., Puttaswamy → Right to Privacy as part of Art. 21 → basis for later challenges to data laws and Aadhaar.
✅ UPSC Focus: Doctrine-to-definition matching · Case-to-holding matching (a very common Prelims format) · Sequence of judicial evolution on Article 21 · Basic Structure-related cases in chronological order.

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