"The rain began again. It fell heavily, easily, with no meaning or intention but the fulfilment of its own nature, which was to fall and fall"

In this quote, the author is describing the rain as a force of nature that is merely following its own natural course. The rain is not actively trying to attain anything or make a declaration, it is just doing what it is implied to do - fall. Using words like "heavily" and "easily" recommend that the rain is both effective and uncomplicated in its actions. This could be viewed as a metaphor for life, where things may occur with no specific intent or significance, however rather as an outcome of their own intrinsic nature.