One is that it negates the person's consent to an act, such as sexual activity or the entering into a contract; or, secondly, as a possible legal defense or justification to an otherwise unlawful act.
其一，它否定了人對該行為的意願，如性交或訂立合同；或者，第二，對於非法行為作為一個可能的法律辯護或理由。