But with respect to the soul, whether it is derived from the seed by a process of traducianism, so that the reason or substance of it may be considered as placed in the seminal particles of the body themselves, or whether it has any other beginning; and this beginning, itself, whether it be by birth or not, or whether bestowed upon the body from without or no, is not distinguished with sufficient clearness in the teaching of the Church.
Origen
On First Principles, Book I
Preface