All moral instruction must be immediate and concrete : it must arise out of a situation which has grown up naturally, and must not go beyond what ought to be done in this particular instance. The child himself will apply the moral in other similar cases. It is much easier to grasp a concrete instance and apply analogous considerations to an analogous instance than to apprehend a general rule and proceed deductively.
Source: On Education, especially in early childhood, 1926, Pt. 2： Education of character, chap. 9: Punishment
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