Stupidity is a moral flaw, not an intellectual one. Some people are highly intelligent but are fools; others have low intelligence but are not fools at all. As products of certain specific environments, we are surprised to discover this situation—true stupidity is not a lack of brains, but a heart that chooses to be closed off. When a person actively gives up independent thinking and turns a deaf ear to the voice of conscience, they fall into this moral flaw. This is not an intelligence issue, but a result of inner choice.