What do "contradictions" mean in Buddhist philosophy?

I read another answer here which discussed avoiding actions that lead to "contradictions" (such as lying, stealing), which are considered "evil". The answer was in response to someone else's question about where does the concept of morality come from in Buddhism. A contradiction means "a combination of statements, ideas, or features of a situation that are opposed to one another". I'm not really sure I understand what the "contradiction" is with stealing, for example.