Creationists often complain that naturalism belittles emotion. It allegedly reduces profound feelings to chemical reactions. This is, I believe, a false dichotomy: emotions can be profound and chemical at the same time.
But there is another rather intriguing implication of naturalism (one that may actually be true!), and it applies to other animals, especially other mammals. As a Christian, I used to wonder if other animals could experience profound emotions like love, given that they weren’t made in God’s image as we supposedly were*.
In a naturalistic framework, though, it seems reasonable to conclude that animals do, in fact, experience these emotions. This is because feelings of love (and other emotions) are essentially nature’s way of tricking us into adopting certain adaptive behaviors. Evolution doesn’t hand each animal an instruction manual laying out cogent arguments for reproducing, eating, etc. Instead, it develops brains that are hardwired to reward adaptive behaviors and punish non-adaptive behaviors. We experience these rewards as love (and other positive emotions) and revulsion (and other negative emotions).
The feeling of love for one’s partner or spouse is adaptive because it prompts us to care about the welfare of another being long enough to produce, and care for, offspring.
And, given that all of today’s mammals have a common ancestor, it seems likely to me that the basic sensation of love, evolved as a reward for stable partnerships, is common among most, if not all, mammals. It is quite possible, then, that love really is all around us.
* I also seem to remember C. S. Lewis making a rather odd argument that it is impossible for people to truly love their pets and other animals, but I’m afraid I don’t remember the gist of his argument. Suffice it to say that I do not agree with this sentiment – it didn’t convince me when I first read it as a Christian, and it doesn’t convince me now.