The human race's prospects of survival were considerably better when we were defenceless against tigers than they are today when we have become defenceless against ourselves.
当我们对老虎没有防御能力时，人类生存的前景比我们今天对自己没有防御能力时要好得多。
当我们对老虎没有防御能力时，人类生存的前景比我们今天对自己没有防御能力时要好得多。