What is the soul?

Living creatures do not possess a "life force." There's no such thing as "life force." Living things are animated by the chemical reactions that go on in their cells, and what drives those reactions is merely the fact that some arrangements of electrons in and between atoms are more stable than others.Aside from the chemical energy produced by the formation of chemical bonds, there's nothing that could be described as "life force." And that chemical energy is not specific to living things, but present in all chemical reactions and interactions.There's no such thing as "life force."

There's a difference between water and ice, too, and it's the same difference."Spirit" has nothing to do with it.