The Enchiridion by St. Augustine
Chapter 86.--If They Have Ever Lived, They Must of Course Have Died, and Therefore Shall Have a Share in the Resurrection of the Dead.
And therefore the following question may be very carefully inquired into and discussed by learned men, though I do not know whether it is in man's power to resolve it: At what time the infant begins to live in the womb: whether life exists in a latent form before it manifests itself in the motions of the living being. To deny that the young who are cut out limb by limb from the womb, lest if they were left there dead the mother should die too, have never been alive, seems too audacious. Now, from the time that a man begins to live, from that time it is possible for him to die. And if he die, wheresoever death may overtake him, I cannot discover on what principle he can be denied an interest in the resurrection of the dead.