The 'sunset limited'
Because in the end, White still lives a Neo-nihilist, in a world filled with pain and anger and platitudes, and it is largely of his own creation. White was a professor, with a clear intellectual advantage, arguing with someone who believed - not only someone who believed, but was a good person. White won the argument - NOT because his belief was right, but because his words were stronger.
When Black collapses during the final speech - it is out of frustration. He can argue with White - he has the feelings, and the faith, and the goodness. However, because he wasn't as well educated, he doesn't have the WORDS. He lost, because White resorted to his "bag of tricks" - his language.
A sunset - the sun going down, and plunging the world into darkness - is limited. There can only be so many, as White believes, nothing lasts forever. everything dies. The FINAL SHOT, however, is of a sun rise. Sure, they too are limited, but no more so than a sunset. The sun rises because Black carries on. In the end, Black carries on, using what little time and money he has, putting his own life at risk, to help his fellow man. White, with all his words and tricks, leaves to destroy himself. He is worthless because that is what he chooses.
By the way, not that this has ANYTHING to do with ANYTHING, but I'm an atheist. That apparently counts here.
Because we know TMNT III: Turtles in Time is about McCarthyism
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