Explain its nature and necessity.

Discretion — the power's choice: the authority's room to decide (the yes-or-no, the how-much, the when) within the law's limits. The statute cannot foresee every case; the general rule needs the specific judgment — discretion is the law's necessary servant. The nature: Unavoidable: no statute can eliminate the case-by-case judgment (the licensing authority must weigh THIS applicant); Lawful only within limits: discretion ≠ arbitrariness — the choice is bounded by the statute's purpose, the relevant considerations and the constitutional rights; The power-and-duty blend: the modern view — the discretion's exercise as a DUTY (the power to decide implies the duty to decide; the non-exercise itself unlawful); The scope's faces: the licensing decisions; the prosecutions' launch; the appointments and transfers; the sanctions' gradation; the policy's implementation; the emergencies' response.