EWTN Catholic Q&A
What is the difference between a human soul and the soul of a plant or animal?
Question from Cameron McNamara on 10-16-2012:

What is the difference between a human soul and the soul of a plant or animal or bug? Following Christ in the World by Seton Home Study School (I think thatís who itís byÖ) says that the soul of a plant or animal isn't immortal. Aren't all souls spiritual beings, and therefore immortal? Or will God discontinue supporting all plants and animal's souls life after the physical part of the plant or animal dies? How are their souls so different that they canít even think? Why do they need a soul?

Answer by Richard Geraghty on 10-25-2012:

Dear Cameron,

All bodies have forms which make then what they are. While all are bodies, some are inanimate and so only have forms which make them bodies of iron, air, water, coal or diamonds. Living bodies also have forms. But in their case the forms are called soul because they are the forms which make bodies alive. Plant souls enable plants to feed themselves, grow and propagate. Animal souls enable animals to do all of the above but also to sense things. They are aware of what's around them and so can approach and eat them. The soul of man enables men to do what animals do plus giving them the ability to reason. Having this ability indicates that that they are purely immaterial souls (spirits). Being immaterial, they have no parts and so cannot be destroyed by poison, guns, clubs, disease and the rest. Once in existence they will live forever either in eternal bliss or misery. But the souls of animals, not being spirits, do not survives their separation from the body. Their souls exist until the animal dies. Then they are no more.

Dr. Geraghty