I admit that I like the "babies and animal" argument as well as "it's as obvious as snow is cold, fire is hot."
However, I always come back to why anyone does anything. For Stoics, being virtuous - or being perceived as acting for virtue - provides them with a sense of satisfaction. To me, satisfaction = pleasure. For Christians, believing in an afterlife appears to bring them joy. Joy = pleasure. For Buddhists, ridding oneself of desires brings contentment. Contentment = pleasure. And so on down the line. To me, there's no escaping it.