User blog comment:TheUnknown285/My Mass Effect 2 Review/@comment-5274392-20120726041053/@comment-174.112.200.161-20120728132404

"As for the theme, Bioware has said through their games that it's synthetics vs organics, which ME2 does not follow."

ME2 shows that it's not exactly as simple as "synthetics vs. organics". Through Legion, we can see that not all of the geth wish harm to organics or even the creators who attempted to extermine them. EDI and Joker's cooperation saves the Normandy from the Collectors. Most importantly, it reveals that the Reapers are not pure synthetics but a combination of organic and synthetic material.

Nonetheless, organic/synthetic relations is only one of the themes prevalent throughout the series as a whole.