Do Not Go Gentle into That Good Night

The four stanzas after the first one of Dylan Thomas' Do Not Go Gentle into That Good Night characterize the different type of men in the world.  He specifies how these men will die and how they may view death.  "Good men, the last wave by, crying how bright"(Thomas, 968).  In this stanza, he states that the good men that eventually die should still resist that death.  He characterize four types of men total with that sort of classification.  For that classification, he uses the phrases "Do not go gentle into that good night." For the second phrase, he uses "Rage, Rage against the dying of the light."  Both of these phrases emphasize a type of rejection to the metaphor that both of these represent: death.
At the end of the poem, the final stanza wraps up why he was talking about these various men and how they all fight death in certain ways.  By stating to his father both of those phrases, he characterizes him as a wise, good, wild, and grave man.  Each one of these characteristics was given to the father by the use of those two phrases.