"Do Not Go Gentle into That Good Night" is an intensely personal poem, written by Thomas to his dying father. David John Thomas was ill for the last several years of his life; Dylan Thomas probably wrote the poem in 1945, but it was not published until after his father died in 1952.
Thomas refers to the ways in which the aged loose their influence as time goes by and affirms their anger and frustration against their situations.
wise men...know...their words had forked no lightning...
good men...crying how bright Their frail deeds might have danced...
Wild men who caught and sang the sun in flight...Do not go gentle into that good night.
Thomas's role in this poem is that of a bereaved son, pleading with his father to hang on to life a little longer. Thomas begs for his father's blessing, or even for his curse - anything that will allow him to remain alive and present. The poem gives voice to Dylan Thomas urging his father to fight against death, "that good night...the dying of the light."