It's a material force that his rhetoric challenges and relies on, gives him a means of getting off the ground, and a means of always getting back to it, too.

这是他的修辞所挑战的并且依赖的物质力量，这种力量给他离开地面的方法，也给他回到地面的方法。

耶鲁公开课 - 现代诗歌课程节选