But it is the position of the State of Texas that, upon conception, we have a human being, a person, within the concept of the Constitution of the United States, and that of Texas, also. We can only go to what the teachings were at the time the Constitution was framed. We have numerous listings in the brief by Mr. Joe. He quoted Blackstone in 1765, and he observed in his Commentaries that the right to life is inherent by nature in every individual, and exists even before the child is born. It is here that we begin to see the root of confusion in the above discussion.
Biologists are never ambiguous about the beginning of the physical life of organisms.
In the case of sexual reproduction, it is at the moment of fertilization. Justice Blackmun however is asking that biologists should be authorities also on the beginning of the personal life of a human being, which is proper to the philosopher. It concerns itself with the body, not the metaphysical status, of the human being. The historical foundations for this confusion is too lengthy to review here. Basically, the scientific revolutions of the last three hundred years have produced as many different languages as there are sciences.