Every political good carried to the extreme must be productive of evil.

Wollstonecraft’s line expresses a caution against political absolutism: even reforms or principles that are genuinely beneficial can become harmful when pursued without limits, balance, or attention to human realities. The remark fits her broader habit of resisting dogma—whether inherited tradition or revolutionary zeal—and insisting that political arrangements be judged by their effects on virtue, liberty, and everyday life. Read this way, the sentence is less a rejection of “political good” than a warning that unqualified, single-idea politics (e.g., liberty without responsibility, equality without justice, security without rights) can flip into its opposite and produce new forms of oppression.