For it seems to me, dear, that the gods with great
 discernment have coupled together male and female,
 as they are called, chiefly in order that they may
 form a perfect partnership in mutual service. 
 For, in the first place, that the various species of
 living creatures may not fail, they are joined in
 wedlock for the production of children. Secondly,
 offspring to support them in old age is provided by
 this union, to human beings, at any rate. Thirdly,
 human beings live not in the open air, like beasts,
 but obviously need shelter.