So in this context, the river of oblivion serves an obvious purpose in the context we have here in Book Two.

故在这部分文本中，遗忘之河便是为了遗忘而存在的,在第二册书正是这样体现的。

耶鲁公开课 - 弥尔顿课程节选

One of these little details that Milton has lifted rather directly is that of the river Lethe, the river of oblivion that was believed to flow in the underworld.

其中弥尔顿直接盗用的一个小细节,是遗忘之河，即忘川,忘川被认为在地狱流淌。

耶鲁公开课 - 弥尔顿课程节选