Because of the way my head works, I think that for me it is best to start the series with Sub-Human. This what I chose to do, so too late now. David Simpson discusses the (dis)advantages of the two ways to read the series.
I see Sub-Human as a story about who has the right to definitions and the lengths to which people will go to enforce their definitions upon others.
What is intelligence?
At what exact point do 1’s and 0’s come to life?
What is a human?
What arguments do we use to justify killing others so we can be “right”?
The Purists are fine with injecting certain soldiers with “nano-infusions”. Yet these infusions change people into super-humans/super-soldiers who can withstand extreme conditions. The Purists are also fine with using dirty bombs to destroy those they consider techno-friendly. Nor are they afraid of killing their own people. In fact, I think it would be safe to say that the Purists represent what I would call an extreme point of view. Yet I sometimes wonder if those kinds of views are becoming increasingly popular because they seem to hold uncomplicated answers.
When the soldiers from the US go on a mission with an AI robot that specializes in heavy trauma suspended animation body bags it makes me wonder exactly who it is that profits from the Purists being in government. Have those who profit been able to use their long-term thinking caps? Hmmm.
Seen from my point of view I found Sub-Human a realistic portrayal of the idiotic decisions we humans make over and over again. A look back into history will show us a frightening tendency toward self-destructive behavior, except now our weapons are a bit more destructive than they used to be. It also clearly shows how hypocritical we are when our own lives are on the line.