The human soul is created since the soul does not arise by emanation, nor by generation, but by creation.48
Consider each of these three parts.49
Emanationism is the Pantheist position, also held by Manichaeism and recently Theosophism, which holds that the soul is
a flux from the substance of God. This is not possible for three reasons. Since God is simple, there are no parts of God to
emanate. Secondly, God is not mutable, which would involve potency; God is all act. Thirdly, the substance of the human soul
cannot be said to be the actual substance of God Himself because either every soul would be part of the substance of God (impossible
for then God would not be simple); or God Himself would be the soul of every human (impossible for the human soul is mutable,
limited and imperfect).
Generationism holds the soul arises from the parents, materially according to Tertullian, or spiritually according to St.
Augustine and Rosmini. This is not possible in the case of material generation, since the soul is spiritual. This is not possible
in the case of spiritual generation since "spiritual seed" is a figment of the imagination, cannot come from the parents since
the souls of the parents have no parts, or if the soul of the human child, generated by the parents, came from two parents,
then the child would have two souls.
Creation holds that God produces each individual human soul from nothing of Himself or from nothing of the subject. The
human soul is created according to two arguments. First, the origin of a thing ought to correspond and be proportioned to
its actual nature; but man’s nature is intrinsically independent of matter which the soul informs, so man’s origin
is independent of matter. Secondly, whatever is new arises from generation or creation. But the soul is not essentially (per
se) generated because it would be a composite (but the human soul is simple); nor is the soul accidently (per accidens)
generated by eduction from material because it would be intrinsically dependent on material (it is not intrinsically dependent
on material since it is spiritual). Therefore the soul is created. Only God can create ex nihilo.
Human parents are true parents, since although God is the true cause of the human person, God is not the total cause. Human
parents are also the true cause of the composite of body and soul, in which the child or the human person essentially consists.
Generation is an act essentially productive, not of a simple thing, but of a composite of material and form. The child generated
is not only a soul, nor is the child only a body, nor is the child only a body and soul accidentally united, but one single
substantial composite, arising from the substantial union between body and soul.50 Therefore, the cause of the
rational soul is God alone; the parents are the cause of the composite which is the union of the rational soul created by
God with the predisposed material provided by the parents preparing, in virtue of the semen and ovum, a body apt for the reception
of the soul, which according to the laws endowed by the God of nature, requires itself to be informed with a rational soul.
A posteriori arguments for the existence of the soul also exist. Klubertanz51 asks whether man has an
ultimate principle by which he thinks and lives? He answers that in living and knowing, man immediately, although obscurely,
knows that there is an ultimate principle by which he knows and lives. Is that principle distinct from the body? Yes, Klubertanz
answers, for when a man dies the body remains as a corpse.