Individual households do not live in isolation; and there are for this fact two closely allied reasons.

If they did there could be no marriage; there could also be nothing like social intercourse.

It is social intercourse of a more or less extended kind that alone makes possible, not only love and marriage, but most of the pleasures that give colour to life.

We see this in all ranks and in all stages of civilisation.

Savages meet together in numerous groups to dance, like civilised men and women in New York or in London.