should be set is naturally different in different countries. It should be higher, of course, in those that are rich than in those that are poor. But everywhere, I hold, some system of standards should be set up, and the lapse below any one of them should be made the occasion of intervention by the public authorities. For this position a good defence can, in many instances, be made upon grounds of economy; for expenditure of State moneys, so arranged as to maintain the efficiency of the poor, may often be profitable expenditure. But, even where this ground fails, the policy that I have sketched is amply maintained: for it is no more than the acceptance in fact of the compelling obligation of humanity.
If this much be granted, the next step in our enquiry is to work out the general conception of a minimum standard in its special application to housing. This task is not so simple as it seems; for satisfactory housing accommodation is a complex conception, involving several elements. Of these two have long been recognised. The first has to
