In contrast to the concrete roots of language, which kept early man communicating like a gorilla with a kitten, modern language is conceptual and contextual.
Therefore, a racial slur by itself means nothing more than what we assume it means. We care much more about how words are used in a sentence, because only that gives ideas meaning.
Only a robot would think the phrase “that guy is a Chink” and the phrase “I hate Chinks” were equally offensive.