Philo Judaeus De Ebrietate 13

[13] Thus, at all events, the lawgiver is very indignant with all uninstructed and unmanageable persons, more than he is with any other description of people whatever. And a proof of this is this: who are they who are united in alliance not so much by study as by nature, whether among men or among the other kinds of animals? No one; not even a madman would say that any beings were so closely united as parents and children; for even by the mere untaught instinct of nature the parent always cares for his offspring, and in every case endeavours to provide for its safety and durability.