Is it possible to live without a heart? Is it possible to feel without feeling the burning sensation inside the chest? Is it possible to empathize relying only on a logical understanding of what is pain, and what is joy? The answer seems simple: with sufficient experience, and knowledge of the experience of mankind, we can say with certainty that there is pain, and that there is joy. But whether it will be an airy answer for one creature that feels at this moment. Only true empathy allows to answer this question correctly.