“The most important part of education is right training in the nursery.”
The dialogue stresses that education begins through early habits and guided play, well before formal lessons. Its claim belongs to the plan for raising citizens in an imagined polity.
Source details
Laws, Book I, Benjamin Jowett English translation. The Athenian Stranger says this while explaining why childhood play and practical imitation should prepare future capacities; it is a program of civic upbringing, not a present-day evidence-based educational standard.