Explain how fulfilling the responsibilities and duties of citizenship secure the common good.

The common good here is the well-being of a county (if the country is prospering, so are the people). The well-being of a country is dependend on everyone fullfulling their duties and responsibilities. In a way this is assumed on a trust basis: I fullfill my duties and I expect that others do too, so that I can benefit from other's work the way they benefit from mine.

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