Quintilian, Institutio Oratoria, Book 4
Harold Edgeworth Butler, Ed.

[42] Some therefore divide the exordium into two parts, the introduction and the insinuation, making the former contain a direct appeal to the good-will and attention of the judge. But as this is impossible in scandalous cases, they would have the orator on such occasions insinuate himself little by little into the minds of his judges, especially when the features of the case which meet the eye are discreditable, or because the subject is disgraceful or such as to meet with popular disapproval, or again if the outward circumstances of the case are such as to handicap it or excite odium (as for instance when a patron appears against a client or a father against a son), or pity (as when our opponent is an old or blind man or a child).