Why should everyone have to live by what you find reprehensible?
We already live in a society where everyone has to live by what others find reprehensible. That's why we outlaw murder, prostitution, drug use, etc. If he defines abortion as the wrongful taking of an innocent life, and defines that growing human baby in such terms, then you can see how pro-lifers come to that conclusion.
I'm sure you're both in support of the illegality of murder. You wouldn't be on his case for supporting the banning of murder. It's just your definition of what "murder"
is that is different.
(I'm pro-choice personally, but I understand his point of view and sympathize with his feelings)
I'm pro-sentience. I don't favor abortion once the fetus has brain activity. In such cases, I'd prefer to allow it only when there is a health risk to the mother. However, while the embryo is still a lump of dividing cells, I have no issue with terminating the pregnancy.
This is another well-thought out and defined position that while contentious with a more pro-life opinion, is just as valid and supportable with evidence.
My Philosophy of Mind professor winced at your equating brain activity with sentience.
I'd be more curious in seeing what
you wince at rather than what your lofty professor thinks, who is just as ignorant on the subject as everyone else on the planet.