I think "the right thing" implied by "civil" in "civil society" means equal say in legal matters, immediate calling out of corruption and full transparency requirements, rule by pre-established and mutually agreed-upon laws, absolute adherence to pre-agreed human rights that require total consensus to alter, etc.

Therefore you can re-read the sentence as:

> Civil society only exists when there is a collective general trust that most people are trying to uphold those shared rules and principles, even when doing so is inconvenient or runs against their immediate self-interest.