Pith means ‘true nature’ and substance refers to the ‘the most important part of something’. The doctrine of pith and substance becomes important when a law made by parliament encroaches upon the domain of the state or vice-versa.
According to doctrine of pith and substance if the encroachment is incidental and true nature relates of the law relates to the subject which is in the domain of legislating authority (centre or state), then law can not be declared invalid on ground of encroachment into subject area of others.
Related articles:
