I like that description of the Soul! Yes, if your Soul died, you would, too. The Soul is the animating force that makes you "alive." It is a piece of Divine Source, and it is how we receive vital force energy from Source.
BUT thought does alter the Soul - the reason we come here into a third-dimensional existence is to experience Soul evolution and growth. We come into an environment of free will and free choice. Through the choices we make here in the physical, we actually allow our Soul to advance - or not.
You can't separate the physical, mental, and spiritual - they are reflections of each other. Remember, all is One. Here in the third dimension, though, we create through conscious intent, so our thought energy very powerfully affects the Soul.
Blessings,
Andrea
Intuitive Consulting with Andrea Hess: Soul Profile and Spirit Guide Readings, Intuitive Development, Unlock Your Intuition