This episode is one of the two best of all of science fiction television, both of them from Star Trek TNG. (The other is "The Inner Light").
These episodes epitomise why science fiction is the best of all fictions, of all storytelling: The best stories are about people, and science fiction allows us to explore people in any imaginable situation, thereby providing the highest levels of insight into the human condition.
This episode is a triumph for the writer, Michael Wagner.
In this episode, we see the ultimate choice of how one wishes to live one's life in relation to others, on the most fundamental level. To be a being of hope and peace, of love and glory, or to choose an alternative, is brought to mavelous life in the characterof Kevin Uxbridge (John Anderson).
In him, we see his passion, his pain, his futile attempts to hide his suffering for his own actions, even to himself. And in this, we see ourselves and our own petty problems in true perspective.