Deus Ex Machina (n)- literally, god from the machine.
Conflicts always make for the best stories. Whether it’s the conflict between countries or lovers or even sporting teams, great stories are almost always the by-products of conflicts that mean something. If the writers of Deus Ex: Human Revolution (DXHR) are to be believed, the greatest conflict is between the concept of a man and the potential of what a man could be. Other games have touched on various philosophies and real-world concepts. Bioshock did so with Objectivism and the question- to what extent is the individual more important than the collective? Dragon Age: Origins (and Dragon Age II at a much, much shriekier level) looked at racism within a fantasy setting.
If the writers of Deus Ex: Human Revolution (DXHR) are to be believed, the greatest conflict is between the concept of a man and the potential of what a man could be.
Deus Ex: Human Revolution instead turns the beacon inwards and consequentially, the questions it asks go much deeper. Its main philosophical thread is one of trans-humanism or how man can become more than human through convergence with the machine. There are also multiple themes pertaining to racism, objectivism, and the 'science vs. ethical boundaries' debate which prove that in Deus Ex: Human Revolution we have a rare-species- a thinking man's game, an anti-Call of Duty-Battlefield-Medal of Honor game, which is a refreshing change.
Zeke Sanders is one of the many antagonists you'll meet.
The Story of the Singularity
"I have argued that we cannot prevent the Singularity, that its coming is an inevitable consequence of the humans' natural competitiveness and the possibilities inherent in technology"- Vernor Vinge
Since Deus Ex: Human Revolution is a prequel to 2000's Deus Ex, it's still set in a world that's debating the advantages of mechanical augmentations to erase limitations set by the physical body. While Deus Ex's world was arguably post-human (since most NPCs you interacted with looked up to your nano-augmented JC Denton as some kind of a superhuman), Human Revolution's world is struggling to accept augmented humans. While there are massive corporations involved in augmentation technology in DXHR's 2027, it's still being heavily debated in society (similar to the fracas surrounding stem cell research today). You begin the game as a completely human Adam Jensen (apart from an almost impossibly pointy beard) but a grave injury causes you to be augmented, thrusting you right in the middle of the conflict.
David Sarif is Adam Jensen's boss & CEO of Sarif Industries.
This is where the scope of Human Revolution's story differs from the original Deus Ex's. While the 2000 game had a large overarching plot which promised and then revealed multiple conspiracies and characters with different motives, Human Revolution has a more personal story. It's more about you as Adam Jensen, the way you perceive things and the choices you make. There are still a large number of characters you interact with but the story feels somewhat smaller compared to its predecessor. Also, the main motive behind many characters in the original game was the search for the perfect society, or Thomas Aquinas' "City on the Hill", as one character in the game looks at it. The focus on society and the many parties wanting to shape it made Deus Ex a game with a much larger scope than Human Revolution. Human Revolution instead specifically deals with the story of mankind "improving" itself using technology and focuses on that theme by telling one man's story.