Yes, the canonical sources quoted are helpful. His analysis seems flawed at this point though:
The ethical quality of karma has much to do with the happiness or suffering that one deliberately inflicts upon another. When the other is incapable of feeling pleasure or pain, such considerations become irrelevant.
That is exactly the rationale that was used to justify animal cruelty, 'animals nervous system are not very sensitive', thus humans can relax and torture freely.
Taken in context (rather than isolated on its own, out of context), Ajahn Brahma's analysis, pertaining to the primitive embryo, is a statement of fact rather than flawed. Ajahn Brahma's analysis is not the rationale that was used to justify animal cruelty because animals have a fully developed nervous system where the embryo does not.
Will wrote:Also, I think kamma has more to do with the mind of the actor, not the subject of any action. That is, having in mind any negative feeling from ridding one's (or another's) body of an unwanted creature - the embryo or fetus - is still implanting negative kamma in our mindstream.
Yes. This consideration is valid. The mind of the actor must bear instinctual negative sorrow & regret that may arise & reconcile these feelings with their intention. Ultimately, Buddha taught kamma is intention (rather than feeling vedana). Women often abort due to believing they are not in a position to take the many year responsibility for a new life, due to personal, financial, social, etc, deficiencies. Their intentions are often based in concern & fear rather than in violence & hate. Attempting to examine their state of intention may be more profitable than rigid moral fundamentalism. Of course, it is ideal a women carry the pregnancy & place the child for adoption but Buddha explained the world is not an 'ideal' place but, instead, a world fraught with ignorance, craving & suffering.