I agree. Your comment reminds me of Star Wars episode Part III and Part VI. Darth Vader let his love for Luke's Mom lead him to the Dark Side. He took on vengence for his wife. In episode VI, Luke defeats his dad and the universe is balanced. Darth Vader (-1) plus Luke Skywalker (+1) = 0 (balance).
The other issue on a less theoretical note is... Is love always unconditional? (this may need to go on another post). I think love is always conditional. Parents love for children in biological terms is conditional because the kids carry the genes. Parents love for each other is also conditional b/c they give each other financial, emotional, and physical needs to each other.
