I don't know if you'll know how to answer this (or if I even know how to ask it), but I was grappling with the question of what is the soul?The soul is the animating principle, that which gives life to a thing. It is the power that sets the body and all of its inner-workings into motion. We die when the body becomes so impaired that the soul can no longer animate it. Here are a few definitions from Catholic scholarly sources:
- New Advent: Soul -- The soul may be defined as the ultimate internal principle by which we think, feel, and will, and by which our bodies are animated.
- Catechism of the Catholic Church, 2nd ed., Glossary: Soul -- The spiritual principle of human beings. The soul is the subject of human consciousness and freedom; soul and body together form one unique human nature. Each human soul is individual and immortal, immediately created by God. The soul does not die with the body, from which it is separated by death, and with which it will be reunited in the final resurrection (363, 366; cf. 1703).
- Modern Catholic Dictionary: Soul -- The spiritual immortal part in a human being that animates his body. Though a substance in itself, the soul is naturally ordained toward a body. Separated, it is an incomplete substance. The soul has no parts, it is therefore simple, but it is not without accidents. The faculties are its proper accidents. Every experience adds to its accidental form. It is individually created for each person by God and infused into the body at the time of human insemination. It is moreover created in respect to the body it will inform, so that the substance of bodily features and of mental characteristics insofar as they depend on organic functions is safeguarded. As a simple and spiritual substance the soul cannot die. Yet it is not the total human nature, since a human person is composed of body animated by the soul. In philosophy, animals and plants are also said to have souls, which operate as sensitive and vegetative principles of life. Unlike the human spirit, these souls are perishable. The rational soul contains all the powers of the two other souls and is the origin of the sensitive and vegetative functions in the human being.
I understand that we believe that our bodies are material, but the essence of our existance is not exclusively material as it includes a nonmaterial soul. I don't quite understand how this works though. If the egg and the sperm, which are purely material and lack a soul, can join to form a human person, where does the soul come from?The soul comes from God. At the moment that a human being is conceived, God creates a unique soul for that human being.
If human beings are more than material, how is in vitro fertilization or human cloning (embyronic or otherwise) able to create a person with a soul? If we are able to "build" people, does that totally negate the spiritual side of us?Well, regardless of how a human being comes to exist, be it by cloning, or in-vitro fertilization, or naturally through the marriage act, the moment he comes to be he is give a unique soul by God. Nothing we do to assist the process of conception can change that. Even with cloning, the soul of the child is different from the soul of the mother.
I hope that helps. For more information on the soul, see the following links:
- Aquinas on Ensoulment
- Rational Souls and the Beginning
- Souls and Spirits
- What Spirits Are and What They Aren't