What exactly is a soul?
The short answer
The soul is the spiritual principle of the human being: the subject of consciousness and freedom, which with the body forms one human nature. Each soul is individual and immortal, created directly by God; it is separated from the body at death and will be reunited with it at the resurrection.
The Catechism's definition
The glossary of the U.S. Catechism of the Catholic Church defines the soul as the spiritual principle of human beings, the subject of human consciousness and freedom. Soul and body together form one unique human nature. Each soul is individual and immortal and is created immediately by God. It does not die with the body, from which death separates it, and it will be reunited with the body in the final resurrection.
The fuller teaching (CCC 362-368)
- Body and spirit. The human person, made in God's image, is both bodily and spiritual. Genesis expresses this symbolically: God formed man from the dust and breathed into him the breath of life, and man became a living being.
- Two senses of "soul." In Scripture "soul" often means human life or the whole person. It also means the innermost and most valuable part of man, by which he is most especially in God's image: the spiritual principle in him.
- The body's dignity. The body shares in the dignity of God's image because it is animated by a spiritual soul, and the whole person is meant to become, in Christ's body, a temple of the Spirit. Man sums up the material world in himself and gives it voice to praise the Creator. So he may not despise his bodily life but must honor his body, which God made and will raise on the last day.
- One nature. The soul is the "form" of the body: because of the spiritual soul, matter becomes a living human body. Spirit and matter are not two natures joined but one nature.
- Created, immortal. Every spiritual soul is created directly by God, not produced by the parents, and is immortal: it does not perish at death and will be reunited with the body at the final resurrection.
- Soul and spirit. When St. Paul prays that God keep his people's "spirit and soul and body" blameless, this does not split the soul in two. "Spirit" means that man is ordered from creation to a supernatural end and that his soul can be freely raised to communion with God.
- The heart. The Church's spiritual tradition also speaks of the heart, in the biblical sense of the depths of one's being, where a person decides for or against God.