66. What principles did the Privy Council lay down in the Prafulla Kumar case for the Doctrine of Pith and Substance

The principles are:

1. Clear-cut demarcation of powers is not always possible, and overlap is inevitable.
2. The extent of invasion into other lists must be considered to determine the pith and substance.
3. List I has priority over Lists III and II, and List III has priority over List II, but the true view is to determine the substance of the Act.