What does "at" from "at the heart of" mean? Can I say omitting "at" in this case?
"At the heart of" is an idiomatic expression used to mean that something is very important or influential. "At" is part of the expression and cannot be omitted. In this case, the speaker has used "at the heart of" to indicate that success is because of those eight traits. Ex: At the heart of our company is the ethic of hard work. Ex: At the heart of the protestors' demands is the right for equal treatment and basic respect.