What is the theme of the poem "Snake" by D.H. Lawrence?

There are two main themes in the poem: the relationship of people to nature and the narrator's own sense of identity.  

The narrator offers us two possible ways we can relate to the natural world. The first way is to admire the beauty and grace of the snake. Even though the snake has the potential to be dangerous, we are actually in no danger from it if we simply stand by and observe while...

There are two main themes in the poem: the relationship of people to nature and the narrator's own sense of identity.  

The narrator offers us two possible ways we can relate to the natural world. The first way is to admire the beauty and grace of the snake. Even though the snake has the potential to be dangerous, we are actually in no danger from it if we simply stand by and observe while it drinks, appreciating its grace and wildness. The second way to relate to nature is through fear and anger, destroying even the possibility of any form of competition or danger to humanity. 

The narrator initially takes the first stance:

And truly I was afraid, I was most afraid, but even so, honoured still more

That he should seek my hospitality

From out the dark door of the secret earth.

Temporarily, his "accursed human education" and sense of his masculine identity get the better of him, and he hurls a log at the snake. He immediately feels remorse and realizes that the act was petty and in fact morally wrong.