Sextus Empiricus Pyrrhoniae Hypotyposes 3.25.246

[246] And as concerns piety towards parents, the same man states, ¹ in reference to the story of Jocasta and Oedipus, that there was nothing dreadful in his rubbing his mother: ‟If she had been ailing in one part of her body and he had done her good by rubbing it with his hands, it had not been shameful; was it, then, shameful for him to stop her grief and give her joy by rubbing other parts, and to beget noble children by his mother?” And with this opinion Chrysippus also agrees. At least he says in his State: ‟I approve of carrying out those practices—which, quite rightly, are customary even nowadays amongst many peoples —according to which a mother has children by her son, ² the father by his daughter, the brother by his full sister.”