If existence isn't a qualifier property, but we all subjectively detect emotional states in ourselves and others surely it has some measurable subjective existence? Maybe we should just assume emotions exist but can't be quantified. If you can agree to that then Kant's point is moot because there are other descriptive attributes and labels we give to hate, love, anguish, joy, disgust, etc. as a way to gauge what the emotion "is". Liebniz' law does not allow for Love to equal hate. They are discernible and therefore unique and therefore not opposites unless all unique attributes are exact opposites. With emotions being subjective I don't think the magnitude of an emotion will ever match exactly and that's why I have a hard time believing that love has an opposite emotion.
"There ought to be a term that would designate those who actually follow the teachings of Jesus, since the word 'Christian' has been largely divorced from those teachings, and so polluted by fundamentalists that it has come to connote their polar opposite: intolerance, vindictive hatred, and bigotry." -- Philip Stater, Huffington Post
always working on cleaning my windows- me regarding Johari
always working on cleaning my windows- me regarding Johari