Emotions are not just chemicals. They are what your mind experiences as a result of chemical reactions inside your brain. This may seem a needless explanation, but it is important to define things properly before wondering what purpose they serve.
The question assumes that being “just chemicals” is not enough reason to justify existence. This belief stems from a bloated idea of human importance. It says, essentially, that the human condition is something more than “just chemicals”. And because “just chemicals” is a lesser way of being, it is not worth existing as.
We were never anything more than “just chemical”. Ideas about human uniqueness, where we are more than just chemical, are fantasy. And because we have been invested emotionally in such ideas for a long time, the chemical truth of our condition seems to be a step-down.
So here are the facts:
- You are just chemicals
- You do exist
Now the question is, what are you going to do about it? How are you going to live your life in the light of the fact that there is no fundamental difference between you and the natural world. You do not have the properties that you thought made you distinct from the world you live in. When you die, you will be dust and no part of you will move on into imaginary fantasy lands.
I personally find it a liberating thought that I am just chemicals. I can think, explore, love, and learn. I need not worry about violating any divine code or angering any deity. In short, I can decide why I exist.
And so can you.