Lettres à Lucilius Section 10

Quidam ex Peripateticis quartam partem adiecerunt civilem, quia propriam quandam exercitationem desideret et circa aliam materiam occupata sit. Quidam adfecerunt his partem, quam οἰκονομικὴν vocant, administrandae familiaris rei scientiam. Quidam et de generibus vitae locum separaverunt. Nihil autem horum non in illa parte morali reperietur.

Quelques péripatéticiens y joignirent une quatrième partie, la science civile, attendu que celle-ci exige une pratique spéciale et s’occupe de matières étrangères aux
trois précédentes. D’autres y rattachent encore ce que les Grecs appellent οίχονομιχήν, la science de l’administration domestique. D’autres ont fait des genres de vie une classe à part : mais il n’est rien de tout cela qui ne se trouve dans la morale.

Certain of the Peripatetic school have added a fourth division, “civil philosophy,” because it calls for a special sphere of activity and is interested in a different subject matter. Some have added a department for which they use the Greek term “economics,” the science of managing one’s own household. Still others have made a distinct heading for the various kinds of life. There is no one of these subdivisions, however, which will not be found under the branch called “moral” philosophy.