Simplicity is a pleasant thing in children, or at any age, but it is not necessarily admirable, nor is affectation altogether a thing of evil. To be normal, to be at home in the world, with a prospect of power, usefulness, or success, the person must have that imaginative insight into other minds that underlies tact and savoir-faire, morality and beneficence. This insight involves sophistication, some understanding and sharing of the clandestine impulses of human nature. A simplicity that is merely the lack of this insight indicates a sort of defect.
