Translation:Laws are necessary for all societies.
To my mind there is a contradiction in this sentence which applies to so many phrases. The sentence uses the definite article before laws and then omits it before societies, in English it would read "Laws are necessary for all societies" or indeed " Laws are necessary for all the societies" if you had in mind all the societies in eg. a university. In a previous sentence Duo insisted on the definite article before Oligarcy and aristocracy which again is problematic, since in English it would be omitted. I know this arises from differences in the two languages but more attention might be paid to resolving the problem.
English and Greek are really different when it comes to defnite article usage. This sentence wouldn't make sense without the articles in Greek, even if they are ommited in English, and there are cases when definite articles are indeed ommited in Greek, that still confuse some learners, because there isn't something similar in English.
So we keep some articles in English to avoid some potential confusion -with a sentence that's actually making some sense, of course. Don't worry though, I see your point. We will keep an eye on it, thank you for your comment ^.^