Why do people only talk about
Arrival when I am sleeping on here?
I don't have a problem wrapping my head around that. I've been a sci-fi fan since like 5th grade. I think you might be missing my point, though. And I'm not sure how to articulate it better. The fact that the events "already happened" doesn't mean she has no agency. Not telling Ian what she knows is the choice she made/makes/will make because that's who she is/was/will always be. If she was the type of person to tell him, then THAT timeline is what she would have seen. Time is not making her choices for her just because she experiences it non-linearly.
I have never agreed with Martin so much. Like, I agree with him so much I feel I should ask his father for his hand in marriage or something.
I am going to restate what he is saying though, because it is a difficult idea to phrase, and it is a question I care about, and I hope there is point in my doing so.
It should be said however, as a preamble, that the movie, to its dismerit I feel, never clarifies what the rules of time are. It never states whether, with knowledge of time, you are able to change the outcome of a situation or to change a choice. I am going to argue with the assumption that you cannot though, because that is the framework everyone is operating with right now.
Adams cannot change the fact that she is going to have a child. She cannot even change the fact she is not going to tell her soon to be husband about it and all the things it entails. That is preordained. In that we agree.
The important question, however, is, insofar as we make decisions we cannot escape, despite our knowledge of future consequences, why are those the decisions we made or were destined to make? Why was the state of the universe one where Adams had the kid instead of one where she did not? If she had been a woman who had never had children she would have been equally unable to change that post understanding the heptapods than she was in the other situation. So what destines her towards one set of events and not the other one?
The answer is that she makes a decision. At some point she makes the decision and it is the decision she was always going to make. She decides to get pregnant (or at least, not have an abortion) knowing the kid's going to die painfully and she would always have done that. That's the kind of person she is, the kind that takes that deal. She is the kind of person who would not give her husband any say in the matter or warn him of what's coming.
She's a shit human being who gives no thought to other people's feelings or rights when making these decisions. She basically has a kid with a built-in expiration date because she figures the maths' going to add up for her.
Adams does not chance upon a destiny devoid of free will where she has to contend with a life where she is going to have a child. The fact that she is going to have it and the whys and hows of it are entirely dependent on who she is as a person. This is not about learning to live with the fact that you are going to be hit by lightning in three years. Regardless of whether free will exists when you consider time to be non-linear, you still make choices that are revealing of yourself as a person. If she were a good person Adams could never have the future the movie shows us because she would not make those dreadful decisions.
As for the question of allowing someone to exist or not, that's not even a question. Unless we spend 100% of our time copulating and conceiving we are constantly depriving people from the chance of being born. There's always the possibility I could have a brilliant kid in nine months if I impregnated some coed right now instead of typing, but no one's going to regard that kid as existing in any real way. If Adams had a real choice of not having the girl, as per the rules of physics and time of that universe, until she actually had her the bairn would exist as much as my hypothetical coed-spawn.
So we're back at the idea of free will vs destiny?
One thing to consider here in the waffle-hole - why is everyone assuming she doesn't tell Ian ahead of time IF that choice was available to her?
Maybe she did and he accepted her portrayal of this fierce, intense brief life full of both love and joy and pain and loss.
It's been a while since I've seen the film but does she say explicitly that she kept this information from him before conceiving her daughter?
Maybe he bailed because he couldn't see the highs but only could obsess over the lows - sometimes we need the benefit of hindsight to truly appreciate an experience (or the benefit of experiencing it all at once) - it takes far more dogged determination to stay in an unpleasant situation if we have no actual idea of how it will turn out.
To me this is simply the beautiful idea that life can only be truly appreciated by learning to embrace both the agony and the ecstasy. She wrapped her arms around all of it.
The film makes it clear he leaves her when she reveals to him what's going to happen to the yungun.
She wrapped her arms around the agony she deliberately created and would never have existed had she been a real person. It's like a serial killer learning to embrace the pain and hopelessness of life while he rots in prison for his murders. Not my idea of Zen philosophy.