Robert George and Patrick Lee have written a response to a new argument against the following position:
At fertilization, the ovum and the sperm cease to be and something new comes to be — an organism (the embryo) whose genetic constitution and epigenetic state orient and dispose it to develop in the direction of maturity as a member of the species.
This seems an uncontroversial statement to me, but when people think they can benefit by destroying life they craft some interesting arguments to justify their actions. So, the new argument is that if the technology exists to extract the sperm after it has penetrated the egg then the union of the egg and sperm cannot be the beginning of life.
The article is brief and needs to be read, but I will give away the ending for those in a hurry. The process of penetrating the egg irreversibly changes the sperm such that whatever could be extracted after the fact cannot be meaningfully considered a sperm cell. At best, you are claiming the capacity to interrupt the fertilization process and not redefine the new life that exists at the completion of fertilization. Once fertilization has occurred a new single cell human life exists with a distinct genetic identity and orientation and disposition “to develop in the direction of maturity as a member of the species.”
Meaning that the new human life has begun and will move through the stages that all human life must move through during the aging process. An embryo becomes a fetus becomes a newborn becomes a child and eventually becomes an adult who posts blogs and argues that his human brothers and sisters in the earlier stages of our development ought not to be destroyed because their deaths profit the rest of us.