235. Three questions about them: (1) What makes man capable of family life? (2) How does it come to have rights? (3) What ought the form of those rights to be?
236. (1) The family implies the same effort after permanent self-satisfaction as property, together with a permanent interest in a particular woman and her children
237. The capacity for this interest is essential to anything which can be rightly called family life, whatever lower forms of life may historically have preceded it
238. (2) The rights of family life arise from the mutual recognition of this interest by members of the same clan (in which the historical family always appears as an element)
239. Its development has been in the direction (a) of giving all men and women the right to marry, (b) of recognising the claims of husband and wife to be reciprocal. Both these imply monogamy
240. Polygamy excludes many men from marriage and makes the wife practically not a wife, while it also prevents real reciprocity of rights both between husband and wife and between parents and children
241. The abolition of slavery is another essential to the development of the true family life, in both the above respects
242. (3) Thus the right (as distinct from the morality) of family life requires (a) monogamy, (b) duration through life, (c) terminability on the infidelity of husband or wife
243. Why then should not adultery be treated as a crime? Because (unlike other violations of right) it is generally in the public interest that it should be condoned if the injured person is willing to condone it
244. Nor would the higher purposes of marriage be served by making infidelity penal, for they depend on disposition, not on outward acts or forbearances