All species capable of grasping this fact manage better in the struggle for existence than those which rely upon their own strength alone: the wolf, which hunts in a pack, has a greater chance of survival than the lion, which hunts alone.
所有能够理解这一事实的物种在生存斗争中都比那些只依靠自身力量的物种做得更好:成群狩猎的狼比单独狩猎的狮子有更大的生存机会。