This post will make no sense to anyone who isn't a hardcore Halo fan and/or hasn't played Halo 4. So, basically, all of my readers except Shaun. Hey, Shaun.
I figured I'd write all the random thoughts I have about the story of Halo 4, how it pertains to the greater Halo universe, etc.
The Librarian claims that she placed gei in humanity's DNA, guiding their evolution toward specific results. It occurs to me that a huge portion of that gei must have inevitably ended up in the brain of Catherine Halsey, since all of her contributions to the UNSC have been almost-direct copies of Forerunner technology.
The Librarian lists "combat skill" as a geas, but it's not certain if she meant humanity's in general or specifically John's. If it is indeed John specifically (which is possible, given that she is capable of creating gei that lie dormant until hundreds or thousands of generations later), then this may explain why John seems to be a singularly capable, borderline-superheroic character. Furthermore, that may be why Halsey picked John in the first place: she inadvertently picked up on his being different due to the geas.
Cortana is said to be another product of human gei, which makes sense considering that she appears as a blue woman, exactly like the Forerunner ancillas did. However, Cortana is stated by the Didact to be "an evolved ancilla," so she may even be something beyond a normal ancilla. Perhaps this is because she was copied from a cloned human brain?
That's another thing. The Composer was supposed to merge the biological with the technological, effectively transplanting a sentient mind into a technological body. Is this not technically what Cortana is? A biological mind transferred and "composed" into digital form?
Given the innumerable ways that the Spartans mirror the Forerunners, the Spartan-II program, I think, was likely Halsey's way of inadvertently fulfilling her geas. That geas being to create a group of immensely powerful humans for the purpose of acting as primary Reclaimers, capable of stopping threats on the level of the Halo array, the Composer, and the resurgent Prometheans.
This is the first time in a Halo game that Master Chief has been treated with actual respect as a character. He's assertive, takes initiative, and is a focal point of the story rather than just someone walking through it. This is exemplified by the fact that he actually speaks during gameplay, something that works really well.
Del Rio is kind of randomly a jerk, but he represents an important idea. Both John and Cortana are caught in a struggle where neither is sure if they are simple tools to be used by the UNSC in service of humanity or if they are truly human themselves. Del Rio vocally represents the cold, pragmatic side of that struggle, while Lasky gives voice to the opposing view. In the end, Cortana and John take a stand for their humanity by standing up for each other. John refuses to let Cortana be destroyed like simple malfunctioning UNSC property, disobeying an order for likely the first time in his life. Cortana later fights against the Didact, saving John and firmly asserting that she's "not doing it for humanity." It's ironic that by denying the things that supposedly define them as servants of humanity, they actually become more human themselves.
At the end, when John and Lasky have their talk about soldiers being "just people," not machines, John almost seems a bit surprised (from what little can be conveyed through the helmet). Not counting anything before age 6, that's probably the first time he's actually thought of himself as human in his entire life. The fact that he takes off his armor for the first time in three months (technically almost five years, but 4.5 years of that were in cryo) is a huge deal, symbolically. I wonder if he'll have the chance to meet his fellow Spartan-IIs that have survived? Or Halsey? How will once again meeting his "family" further his development as a person?
I wonder what the Spartan-IIs and IIIs think about the IVs, who weren't at all picked or trained the same. Heck, IVs are basically just upgraded marines, not at all like the previous Spartans, who were arguably not even human in the same manner.
I may write more later. Or not. But probably yes.