A poem by Dylan Thomas
written to his father to fight against death: "Do not go gentle into that good night
It consists of both soft melodious tones
and harsh tones
to contrast between life and death
Wise Men are philosophers who rage against death because they don't know if they're right on their philosophies therefore they must live until they are proven right. Also since their "words have forked no lightning", they want their philosophies to make a difference, an impact and they want to see the day that it does. So they "rage against the dying of the light".
Good Men are men who do good, puritans who never sin. They have certain beliefs and they rage against death because they might have "danced in the green bay", they would lose potential of doing that if they died. The ocean is a symbol for timelessness.
Wild Men are men who are opposite to the good men. They are hedonists, they did dance in the "green bay". And because they've had so much fun they do not want to die.
Grave Men are men who understand death but are not willing to accept it. They are burdened with this understanding of death. Poets are under the category of grave men. They see with "blinding site" (ie. Milton)
"And you, my father, there on the sad height,
Curse, bless, me now with your fierce tears, I pray
Do not go gentle into that good night.
Rage, rage against the dying of the light."