What utilitarianism changed

I am reading human action and I read this quote. I thought it was a great explanation of a major difference in thought that began to get more attention once people like Hume, Smith, and Ricardo came along.

"The utilitarian economist does not say:Fiat justitia, pereat mundus. He says: Fiat justitia,ne pereat mundus. He does not ask a man to renounce his well-being for the benefit of society. He advises him to recognize what his rightly understood interests are. In his eyes God’s magnificence does not manifest itself in busy interference with sundry affairs of princes and politicians, but in endowing his creatures with
reason and the urge toward the pursuit of happiness."