[jennyp]

Actually, the human conceptus is in the species of humans, not some other species then suddenly upon arriving at a specific cellular accumulation, instantly into the human species. In logical flow, species designation comes first, then ages of a member of the species, based on form and function.

I see your point, but so what? If I remove a cell from my body, it's a human cell. So...?

An embryo is a human embryo. But it's still just an embryo! Likewise a person whose brain has stopped functioning for the last time is a human cadaver. But the human person doesn't exist anymore.

[Hajman]

I see your point, but so what? If I remove a cell from my body, it's a human cell. So...?

Human cells arn't human organisms. Embryo cells are also different from specialized organ cells: they're totipotent (able to develope into an adult of the species), as opposed to the pluripotent (able to differentiate into any type of specialize cell) and multipotent (able to differentiate into any type of specialize cell in a certain group, such as bone marrow blood cells) stem cells, and the rest of the specialized human cells (which your example falls under).

An embryo is a human embryo. But it's still just an embryo! Likewise a person whose brain has stopped functioning for the last time is a human cadaver. But the human person doesn't exist anymore.

And a baby is a baby, and a child is a child.. all subsets {development stage} of the same set called 'human'. A human dies when their brain dies because the brain is the central life-support system for the body (note that it could be argued that some people with sever head trauma may stop being the 'person' they were, and also in cases of permanent comas, the person may for all practical purposes stop being. However, in these cases, the brain may continue to function as the life-support of the body). A pre-brain fetus can be considered alive because there's no need for a central life-support system at this point. It's still a general life-support system that their body has. This allows life before the brain [has developed], but keeps life from being sustained after the brain [has died].

-The Hajman-

[spunkets]

"An embryo is a human embryo. But it's still just an embryo! Likewise a person whose brain has stopped functioning for the last time is a human cadaver. But the human person doesn't exist anymore."

An old man is a human old man, but it's still just an old man. Likewise a fish whose brain has stopped functioning for the last time is a fish cadaver(dead fish), but the essence of live fish doesn't exist anymore.

[hocndoc]

You are comparing normally functioning complete organisms with dead organisms or portions of organisms.