Which part of the Indian Constitution is called soul of the Constitution?

Which part of the Indian Constitution is called soul of the Constitution?

Dr. B. R. Ambedkar called Article 32 of the Indian Constitution i.e. Right to Constitutional remedies as ‘the heart and soul of the Constitution’.

It was made so because mere declaration of the fundamental right without an effective machinery for enforcement of the fundamental rights would have been meaningless. Also, a right which does not have a remedy is a worthless declaration. Thus, the framers of our constitution adopted the special provisions in the article 32 which provided remedies to the violated fundamental rights of a citizen.