One of society's purposes is also to ensure that all of its members are provided for. That's basically the exchange: contribute to society and society will make

One of society's purposes is also to ensure that all of its members are provided for. That's basically the exchange: contribute to society and society will make sure that your needs are met. Therefore, I would say that taking a portion from those who have an excess and giving it to those who do not have enough is within the legitimate role of society.