They are penned up in filthy houses and left to rot and stew in misery, and the conditions of their life make them ill faster than all the doctors in the world could heal them; and so, of course, they remain as centres of contagion, poisoning the lives of all of us, and making happiness impossible for even the most selfish. For this reason I would seriously maintain that all the medical and surgical discoveries that science can make in the future will be of less importance than the application of the knowledge we already possess, when the disinherited of the earth have established their right to a human existence.”