To Florus 2.176

Let our result be plain: by ‘all,’ the apostle meant very many, whom he says are subject to death because they sinned by their own will. He therefore accuses voluntary crime, not original crime. In fact, if the words’ reliability and proper meaning are weighed, they indicate nothing else. For if he believed sin passed to descendants by generation—that is, was hurled from Adam at people who had not been there—he would speak utterly falsely in declaring that all sinned (compare Romans 5:12).