Do atheists believe humans have souls?
I guess I’m an atheist because I have a naturalistic view of the world where reality is based on what’s physically observable, and nothing is accepted on pure faith. So I don’t “believe” in deities, an afterlife, or a metaphysical soul that somehow spiritually animates our bodies. I reject the notion of anything that stands outside the laws of physics, and whose existence persists after physical death. Ghost stories are entertaining fiction.
If by “soul,” on the other hand, you mean my mind – consciousness, self-awareness, sense of self, unique individual personality, experiences, memories, knowledge, feelings, drives, etc – then of course we all have souls and I think we call this humanism. Our souls somehow emerge from those tangled masses of neurons we carry in our heads. In this sense, when I die my soul dies, too, because all brain function ceases within minutes.
Douglas Hofstadter, writing in I Am A Strange Loop, speaks of creatures having different “sizes” of souls, measured in arbitrary units called Huneckers. A man’s soul is bigger than a dog’s soul, which is bigger than a flea’s (this is subjective whimsy, of course, because even when viewed as a manifestation of neural processes there is no clear definition.) In this sense the word “soul” is a nice metaphor for “mind” but nothing more.
Hofstadter describes things left behind after a person dies – photographs, letters, and so on – as “soul shards.” For example, the printed musical symbols that represent one of Chopin’s etudes in a sense contain a little piece of Chopin’s soul, because some of his thoughts and feelings while he was alive are revealed to us. In this sense, optimistically, the soul may partly survive physical death. If an asteroid destroys Earth then all bets are off.