How has the Indian Constitution ensured …

The constituton provided distribution of legislative powers into the following organs:

1. Union List: Subjects of national importance like defense, foreign affairs, atomic energy, banking, post and telegraph are included in the Union List. Only the central government can pass laws on the subjects mentioned in the union list because we need a uniform policy on important or national issues throughout the country. The union list has 97 subjects.
2. State List: It comprises the important subjects on which the state government can pass laws. Subjects like police, local government, trade and commerce, agriculture are within the state included in the State list. The state list has 66 subjects.
3. Concurrent List: The concurrent list comprises the subjects which are of common concern both to the centre and state government. However if there is a conflict between the central law and state law, over a subject in the Concurrent list, the central law would be effective. The concurrent list has 47 subjects.
4. Residuary Powers: Matters which are not included in the division of powers are known as residuary powers. It was felt that there can be subjects which are not mentioned in either of these lists. The central government has been given the power to legislate on the residuary subjects.