Does Mill demand fully private education?

No. He allows state funding, assessment and, where necessary, provision; he opposes state control of all or most education that crowds out alternatives.

Could a common exam create another monopoly?

Yes. If overly detailed or tied to one pedagogy, assessment can standardise the curriculum indirectly, so it should focus on basic outcomes and remain publicly reviewable.

How can diverse schools avoid poor quality?

Through transparent floors for competence, safety, non-discrimination and accountability, rather than one required worldview or teaching route.

On Liberty

Why Mill supports compulsory education but opposes a state monopoly

Mill separates ensuring that every child is educated from letting the state dictate all teaching. The first protects children; the second can turn majority preference into a single mental mould.

The objections which are urged with reason against State education, do not apply to the enforcement of education by the State, but to the State's taking upon itself to direct that education.On Liberty, Chapter V: Applications

The direct answer: guaranteeing education does not require monopolising its provision

Mill argues that children are not property for parents to dispose of. Society may require an adequate education and help families unable to pay. If the state is also the sole provider and judge of content, however, it can turn the ruling power’s preferences into one mental mould.

Read the Chapter V passage.

Why education may be compulsory

Children cannot yet secure all their long-term interests, while parents bear a definite responsibility for their development. Education is therefore a duty to the child and society, not simply an adult’s private taste. Public authority may set a floor, test whether it is met and fund those who cannot afford it.

Why the state should not be the only teacher

A single system can impress the preferences of a monarch, clergy, class or current majority on every mind. Mill’s concern is not public money as such, but one power controlling access, content and judgment. Diverse providers allow methods to be compared and minority views to survive.

Diversity still needs a common floor

Multiple schools do not mean abandoning quality, child safety or basic competence. Separate common outcomes from routes: publish minimum standards and fair checks, permit different curricula and methods to meet them, and support those unable to pay. A state school may be one option among several rather than the institution that excludes all others.

What a modern reader must add

Testing can itself standardise curricula; market choice is not automatically fair when poverty, geography and discrimination constrain access. Mill’s details are not a ready-made policy. His durable warning is that the duty to protect children must not become permission to monopolise minds—a distinction consistent with harm and proportionality.