Humans will act against self-interest to assert freedom
The narrator argues that if science ever tabulated human interests so that every choice could be predicted like a piano key, people would deliberately do something irrational or destructive just to prove they are not piano keys. The most advantageous advantage is the ability to choose one's own will, even stupidly, so any utopia built on rational self-interest (the 'Crystal Palace') will be rejected out of spite. Two times two makes four is, in his view, the beginning of death, not a good in itself.