John stuart mill was a staunch proponent of

Individual rights.

Explanation:

John Stuart Mill, or more commonly known as J. S. Mill, was a British writer and philosopher who had written on numerous issues, regarding society and even social economy.

In his essay "On Liberty", he emphasized the importance of 'individuality'. He states in the third chapter of the essay that the society ought to give more importance to the individual rights of people, and that it is this individual liberty that promotes the creativity and diversity needed in the society. The actions of a man alone is not what's important but rather the man and the action together are important as a single entity. And the silencing of someone's opinion should not be done. Instead, every opinion must be taken into consideration and it is this democratic approach that will ensure the stability of the society.