The doctrine of eclipse allows pre-constitutional laws that conflict with fundamental rights to remain in effect until those rights are amended, rather than being void from the start. This principle, rooted in Article 13(1) of the Indian Constitution, asserts that these laws are dormant when inconsistent with fundamental rights. The doctrine has evolved through significant case law, reinforcing that while fundamental rights are not retroactive, the eclipse theory provides a protective measure for both pre- and post-constitutional laws.