Riis views the extreme overcrowding and miserable filth of the New York tenements, not to mention the greed of the landlords, as the root causes of crime and alcoholism among the lower classes, most of whom were either recent immigrants or persons of color. Living in a horrible environment causes the poor to be "shiftless, destructive and stupid." He writes:
"By far the largest part--eighty per cent. at least--of crimes against property and against the person are perpetrated by individuals who have either lost connection with home life, or never had any, or whose homes had ceased to be sufficiently separate, decent, and desirable ...
He also notes the alcoholism in tenement dwellers. This too he traces to the lack of decent housing:
"Forty per cent. of the distress among the poor, said a recent official report, is due to drunkenness. But the first legislative committee ever appointed to probe this sore went deeper down and uncovered its roots. The "conclusion forced itself upon it that certain conditions and associations of human life and habitation are the prolific parents of corresponding habits and morals," and it recommended "the prevention of drunkenness by providing for every man a clean and comfortable home."
The "other half" are chiefly immigrants: Germans, Jews, Chinese, Bohemians, Pole, Italians, as well as blacks. Latecomers, they have been shut out of the American dream.
Riis understands the poor, especially the deserving poor, who are primarily women and children, as in need of a much better chance in life, and as capable of becoming integrated into American life. He writes, "it is not an uncommon thing to find sweet and innocent girls, singularly untouched by the evil around them, true wives and faithful mothers, literally "like jewels in a swine's snout," in the worst of the infamous barracks."
On the other hand, the truly indolent and criminal, those who wouldn't work or were hardened so much they would not abandon crime, could not be assimilated into the American mainstream, he thought.
Most of the poor, he notes, work hard, and are not "vicious," but simply can't make enough to live on decently. Blacks too, deserve a better shake. (Riis is racist, but in sympathy with the way the deck has been stacked against the blacks.) He shows his sympathy, if stereotyping, in sentences like the following: "Cleanliness is the characteristic of the negro in his new surroundings, as it was his virtue in the old. In this respect he is immensely the superior of the lowest of the whites ..."
He blames capitalist greed for much of the problem. Landlords charge outrageous rents and evict people who don't pay in advance. Owners and even middlemen exploit the workers. He writes:
The sweater [sweatshop owner] knows well that the isolation of the workman in his helpless ignorance is his sure foundation, and he has done what he could--with merciless severity where he could--to smother every symptom of awakening intelligence in his slaves. In this effort to perpetuate his despotism he has had the effectual assistance of his own system and the sharp competition that keep the men on starvation wages; of their constitutional greed, that will not permit the sacrifice of temporary advantage, however slight, for permanent good, and above all, of the hungry hordes of immigrants to whom no argument appeals save the cry for bread.
The problem, to Riis, is the system, stacked against the poor. Capitalism must be reformed, he said, with trade unions and laws to protect workers and provide them with decent housing. The rampant individualism and lack of social safety net that characterized 19th century America created the problems suffered by the lower classes. They were not themselves degenerate, but made so by circumstances.
Riis is not anti-capitalist. He advocates for stronger laws, but the best remedy for the horrible tenements, he argues, lies in the hands of private enterprise, which can build new tenements and provide agents to deal fairly with renter complaints. Yet the problem must be dealt with:
The sea of a mighty population, held in galling fetters, heaves uneasily in the tenements. Once already our city, to which have come the duties and responsibilities of metropolitan greatness before it was able to fairly measure its task, has felt the swell of its resistless flood. If it rise once more, no human power may avail to check it.