释义:推究古代的事例来验证今天的情况,从而避免困惑;先揣度事情的始末,后仔细考虑,从而应对突发情况。这是对借鉴历史、谨慎行事的智慧的强调。 
The most exciting applications of drones haven't even been invented yet.
All mankind is in a perpetual and restless desire for power after power that ceaseth only in death.