Wasps sting because they are afraid or because they are angry. It goes unremarked that in the opening scene of the famous "Romeo and Juliet" Romeo is groaning with love for some unnamed female that is clearly not Juliet. Emotions move creatures in ways that overawe the meager powers of reason. Rage and love are prods to action with value vested in survival and propagation. The violence and the "other vulnerabilities" made inevitable in creatures subject to emotion have Darwinian implications that seem to be completely invisible to humanity at large. Every song is a love song (with the exception of ballads that tell the tale of some emotion charged escapade). We don't know it, but we tend to love our emotions. We feel that our emotions are the essential truth of our being.
Our emotions are as mechanical as a wristwatch. Wristwatches have purpose and that's why we have them. We don't worship our wristwatch. Emotion has a survival purpose that humanity must come to recognize as "not-self" in the same way as an artist appreciates the brush as "not-self". Emotion tells us a truth about ourselves and not much else about what is real.
Truth, Beauty, and Good are emotional values, and the difference between good and evil is in that which truth beauty and good are found. If we are the pawn rather than the conservator of our emotions we will never be able to know the difference.