Legal Argument
(1) Murder is the taking of an innocent person’s life.
(2) According to the law, a pregnancy is not recognized as a person.
(3) Therefore, abortion is not murder.
Premise 2 is arbitrary. What if the law is wrong? Then, the conclusion must also be wrong.
If everyone wants a good argument with this reasoning, then debaters should agree on a specific definition of personhood that the law can recognize.
The law argument is circular reasoning and irrelevant until the debaters agree on a logical definition of personhood.
Personhood Argument
It's easier said than done to come up with a good concept of personhood. Finding a coherent concept of personhood is a philosophical exercise and a rabbit hole.
Some people think viability is the answer, which I’m unconvinced about.
Many premature births require medical assistance to survive. Requiring medical assistance isn’t the typical idea of viability, which one thinks.
A healthy, full-term baby fits this ideal concept of viability since it can survive without medical assistance. However, most people couldn’t agree with this extreme case of viability since many consider abortion in the third-trimester murder.
However, medical viability depends on the capabilities of advanced medical care, which once didn’t exist and could improve in the future.
The fetus/embryo/(input early stage) is a clump of cells and not a human being
Many people think that a pregnancy is a group of cells that is no more a human being than a foot or hand. However, the pregnancy at conception is a human organism and continues to be the same human organism when it dies. On the other hand, a clump of cells does not constitute a human organism and can’t grow into one.
Therefore, it seems reasonable to say that pregnancy is a human being at the initial stage of their life and continues to be for their existence.
I have tackled what I perceive as implausible arguments for abortion. These are some sources for arguments against abortion that have influenced me.