Having established his central theme in the first half of the poem, that by avariciously pursuing material well-being and possessions we have placed a barrier between ourselves and Nature, Wordsworth changes the tone of the poem towards the end, saying boldly that he would rather be a pagan than lose himself to the continual thirst for money and possessions. In Wordsworth's thinking, pagans had a far healthier relationship than the people of his time, respecting and worshipping nature. Thus advocating their creed would enable him to have "glimpses" of Nature in all its majesty that would enable Wordsworth to become "less forlorn" than he is at the moment when he feels he is cut off or divided from Nature. Note how the mythological references of the last two lines reinforce this idea:
Have sight of Proteus rising from the sea;
Or hear old Triton blow his wreathed horn.
Note how the use of mythology here dramatises the connection to nature. These deliberate allusions create a desire for a time when people were in greater awe of nature and lived "in tune" with it.