The causes which give rise to what are here described as “moral regions” are due in part to the restrictions which urban life imposes; in part to the license which these same conditions offer. We have, until very recently, given much consideration to the temptations of city life, but we have not given the same consideration to the effects of inhibitions and suppressions of natural impulses and instincts under the changed conditions of metropolitan life. For one thing, children, which in the country are counted as an asset, become in the city a liability. Aside from this fact it is very much more difficult to rear a family in the city than on the farm. Marriage takes place later in the city, and sometimes it doesn’t take place at all. These facts have consequences the significance of which we are as yet wholly unable to estimate.

Investigation of the problems involved might well begin by a study and comparison of the characteristic types of social organization which exist in the regions referred to.

What are the external facts in regard to the life in Bohemia, the half-world, the red-light district, and other “moral regions” less pronounced in character?

What is the nature of the vocations which connect themselves with the ordinary life of these regions? What are the characteristic mental types which are attracted by the freedom which they offer?

How do individuals find their way into these regions? How do they escape from them?

To what extent are the regions referred to the product of the license; to what extent are they due to the restrictions imposed by city life on the natural man?

Temperament and social contagion.—What lends special importance to the segregation of the poor, the vicious, the criminal, and exceptional persons generally, which is so characteristic a feature of city life, is the fact that social contagion tends to stimulate in divergent types the common temperamental differences, and to suppress characters which unite them with the normal types about them. Association with others of their own ilk provides also not merely a stimulus, but a moral support for the traits they have in common which they would not find in a less select society. In the great city the poor, the vicious, and the delinquent, crushed together in an unhealthful and contagious intimacy, breed in and in, soul and body, so that it has often occurred to me that those long genealogies of the Jukes and the tribes of Ishmael would not show such a persistent and distressing uniformity of vice, crime, and poverty unless they were peculiarly fit for the environment in which they are condemned to exist.

We must then accept these “moral regions” and the more or less eccentric and exceptional people who inhabit them, in a sense, at least, as part of the natural, if not the normal, life of a city.

It is not necessary to understand by the expression “moral region” a place or a society that is either necessarily criminal or abnormal. It is intended rather to apply to regions in which a divergent moral code prevails, because it is a region in which the people who inhabit it are dominated, as people are ordinarily not dominated, by a taste or by a passion or by some interest which has its roots directly in the original nature of the individual. It may be an art, like music, or a sport, like horse-racing. Such a region would differ from other social groups by the fact that its interests are more immediate and more fundamental. For this reason its differences are likely to be due to moral, rather than intellectual, isolation.

Because of the opportunity it offers, particularly to the exceptional and abnormal types of man, a great city tends to spread out and lay bare to the public view in a massive manner all the human characters and traits which are ordinarily obscured and suppressed in smaller communities. The city, in short, shows the good and evil in human nature in excess. It is this fact, perhaps, more than any other, which justifies the view that would make of the city a laboratory or clinic in which human nature and social processes may be conveniently and profitably studied.