John Stuart Mill 

was given an extremely rigorous upbringing, and was deliberately shielded from association with children his own age other than his siblings. His father, a follower of Bentham and an adherent of associationism, had as his explicit aim to create a genius intellect that would carry on the cause of utilitarianism and its implementation after he and Bentham had died.

-- A biographer or something, not Wikipedia

This worked perfectly.

We're overthinking it. Just raise kids in isolation and train them to be perfect rationalists and Effective Altruists. We'll get an entire generations of Mills.