I did not say that Roe v Wade decided anything based on theological arguments or suggest that religion should decide whether or not a woman has the right to get an abortion. I just noted that the majority opinion in RvW took note of theological/religious as well as philosophical and scientific views of when human life begins.
For people on both sides, abortion involves issues of conscience related to religious beliefs. If religious practice does not involve what is outside one's body, one would expect the right to freedom of religion to apply. The SC noted that not all religions agreed on when human life begins - and it couldn't privilege one - and that not even all scientists agreed. That's why it focused on the law and persons.
The meaning of an utterance lies in its use, and language isn't math. "A human being" is not the sum of its parts, but a new whole with connotations. If your approach were right, "a canine being" could not be a suspect expression for native speaker intuition. Note that the following dictionary definitions include items not necessary if you are right.
Human being | Define Human being at Dictionary.com
1. any individual of the genus Homo, especially a member of the species Homo sapiens.
2. a person, especially as distinguished from other animals or as representing the human species: living conditions not fit for human beings; a very generous human being.
Definition 1 uses "individual" and "member" of a species, and it is NOT universally accepted that a human embryo fits that usage. Definition 2 uses "person," which connotes subjective consciousness. See:
1 U.S. Code § 8 - for U.S. Code › Title 1 › Chapter 1 › § 8, where such expressions as "individual," "human being," and "person" apply to born-alive infants in US law.
human being: definition of human being in Oxford dictionary (British & World English)
A man, woman, or child of the species Homo sapiens, distinguished from other animals by superior mental development, power of articulate speech, and upright stance.
Human being - Definition and More from the Free Merriam-Webster Dictionary
definition for English learners: a person
definition for kids: an individual of the species of primate mammal that walks on two feet, is related to the great apes, and is distinguished by a greatly developed brain with capacity for speech and abstract reasoning
Why do these definitions bother to use "person" or say anything beyond "the species Homo sapiens" or "the species of primate mammal that walks on two feet"? Why note "superior mental development" and "a greatly developed brain with capacity for speech and abstract reasoning" ? The definitions are trying to get in the connotations carried by "a human being."
Your argument, which treats words like numbers added in math, doesn't persuade me at all.
You are the one exhibiting appeal to authority and lack of an ability to think on your own. You google one definition in one dictionary and say, "See? X+Y=X+Y," as if language were basic math. I noted a usage limitation other posters have also noted (e.g., BattleRifle) and explored it from a native-speaker intuitional view with several uses of the expression. Here, I explore several dictionary definitions and relate them to that usage limitation. I explain my own reasoning, treat no single source as an "authority," and analyze in terms of my own thinking.
An education means years in disciplined intellectual exploration of something; a credential requiring that just proves one did it. Anyone might have spent as many years as I did in as disciplined exploration of the same things. If they had, they, too, would pay really close careful attention to the use of English expressions as regards humans, human beings, and members of the species Homo s sapiens.
My point in mentioning my study of anthro and teaching of English just summarizes the fact that I read/heard lots of anthropologists use terms related to humans and thus I know their usages (which do tend to distinguish "a human" and "a human being"). Second language English students present tons of questions about usage because dictionary definitions are insufficient. That explains why I used the linguistic approach of consulting native speaker intuition here.
Show me where your post "applied any real measure of common sense or an ability to think on your own in doing so." You blatantly substitute the authority of one popular dictionary definition for exploration of word usage, careful analysis of language, or anything else that might represent thinking on your own.