In plain words
The path that achieves the progress of society through individuals is itself the distinctive mark of Bhārata's culture: the collective nature, the collective form, the welfare of all beings, the holding together of the world; these are what the ṛṣis of Bhārata chiefly taught and practised.
The Manusmṛti, the Nāradasmṛti, the Yājñavalkya Smṛti and the other Smṛtis laid down as law the disciplines that are the chief foundation for shaping the collective life through individuals. These are what people call śāstra. Except in Bengal alone, the people of all the other states have been carrying out their social duties only within the śāstra system called Mitākṣara; in Bengal the refined system called Dāyabhāga was in force.