f a person is hurt by unkind words, intrigued by subtle points, has a sense of humour, is touched by sad stories, fears death, then we might say he has “a soul”.
Shared human reactions and gestures underlie the language game connected with “soul talk”.
If when someone “smiled”, he had only five positions of his face, and when it changed it snapped straight from one position to another, then we might not be able to respond to him as TO do to a smile, and we might then wonder if he had a soul.