One of my previous students recently wrote me, asking about human clones:
If a person is ever cloned, does that living being have a soul? Can we say that God made that person, and that despite being cloned by man, is still a unique individual? Should a clone of a person have the same rights as a person who is, well, the original? Would it be a sin for a person to allow themselves or to allow others to be cloned?
the soul is defined as the first principle of life of those things which live: for we call living things “animate,” [i.e. having a soul], and those things which have no life, “inanimate.” (Summa Theologia I.75.1)
the human soul is produced by God (Summa Theologia I.75.6)