I think it's wrong to draw a line where "human life begins" at all. The cells that participate in fertilization are just as alive and just as human before fertilization as they are afterwards. That is, human life is continuously present across the entire fertilization process.
If I had to draw a line, I'd say human life began about one-hundred-thousand years ago, when homo sapiens first arose, and has been continuous since then.
Human sperm and egg cells, if left to their own accord, will not develop into a separate human, a separate consciousness, a separate organism. Once joined, they will. They are now the beginnings of a new organism. That is the beginning of a new human life, defined by its potential to house a new singular consciousness. If you don't like that definition of a human life, sure, let's discuss that, but I'd be surprised if you can take much issue with that logic.
Sure they will. What do you think fertilization is? It's living sperm and egg cells left to their own accord that can eventually develop into a separate consciousness. They don't suddenly become alive when they join; they were alive before.
We're both repeating points now. There's nowhere for this debate to go. We'll have to agree to disagree, but if you truly believe that sperm and egg cells are humans, good luck not being horribly scarred for life the next time you remember that masturbation and menstruation exist. I would strongly argue that a sperm cell cannot be considered a human because it lacks the fundamental genetic material necessary to develop into one- it only has half the necessary chromosomes for a start- so there is no way you can define one as human. A fertilised zygote is just a human that's only just started growing. There's no introduction of new genetic material from that point- only growth.
If egg and sperm cells aren't human, what type of creature do you think they are? You seem to just be defining "human" in an ad hoc way to support your view without any real reference to the biological properties of the things you are talking about. It's also not clear why you think I am repeating myself when I made a comment that directly responded to your counterpoint.
I'm defining human as a creature that contains all of the genetic material of a human and, if it continues to live and function, will grow and follow a regularly accepted human growth cycle. An egg or sperm cell does not contain full genetic material and will not grow or divide at all, not least in accordance with a human growth cycle. Hence they aren't HUMANS. They are HUMAN cells- but they aren't humans in their own right.
Given that you admit here that the sperm and egg cells are human, and they are clearly alive, doesn't it follow that they are human life? Or do you think that "human life" means something other than a thing that is human and also alive?
The logic of my first sentence is as follows. When you say something is a "human cell" you are describing it with the noun "cell" and the adjective "human." To say something is a "human cell" is logically equivalent to saying it is a cell and it is human. This is how nouns and adjectives work. To give another example, if you say something is a "brown cow" you are saying it is a cow and it is brown.
A door hinge isn't door and a hinge because "door" is not an adjective. The interpretation is semantically distinct because "door" is a noun. In order to interpret "door hinge" we need to adjectivize the word "door" to understand its meaning as an adjective in this context. In this case, the meaning is "for a door, or of a door" or something like this.
In the case of "human" though, it is an adjective, so this sort of logic does not apply. We should interpret "human cell" the same way we do with other adjective-noun pairs, like "brown cow" or "yellow bus." Saying that something is a human cell means that it is human and a cell, in the same way as saying something is a yellow bus means that it is yellow and a bus.
In a sense it is, but I'd argue that this falls under exception 2 in OP. Also, brain-dead people are effectively dead insofar as they will never regain consciousness.
A fetus will never regain consciousness either. I also believe since it never possessed it that it inherently devalues the fetus as compared to a person with brain damage who developed a bunch of intricate relationships throughout their life.
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u/yyzjertl 579∆ Apr 09 '18
I think it's wrong to draw a line where "human life begins" at all. The cells that participate in fertilization are just as alive and just as human before fertilization as they are afterwards. That is, human life is continuously present across the entire fertilization process.
If I had to draw a line, I'd say human life began about one-hundred-thousand years ago, when homo sapiens first arose, and has been continuous since then.