The requirement for 'purposely doing what the law declares a crime' defines which legal term?

The correct answer is intent, as it fundamentally represents a person's mental state while committing an act that is defined as a crime by law. When the law stipulates that the act must be done "purposely," it indicates that the individual had a conscious objective to engage in the behavior that constitutes the crime. This distinguishes intent from other legal concepts such as negligence or motive.

Negligence involves a failure to exercise reasonable care, leading to unintended consequences, which is not aligned with the definition given in the question. Malice generally refers to a specific intention to do harm or to act with a disregard for human life, which is more specific than simply "purposely" committing a crime. Motive, on the other hand, explains the reason behind an act but does not reflect the intention with which the act is committed. Therefore, the requirement described in the question relates directly to the concept of intent, making it the most accurate choice.