But just what is the problem? The answer to that question depends upon the point of view. In the first place, it must be decided whether it is desirable for nations consciously to interfere with, and try to control, such a natural movement as this; secondly, if interference is to be undertaken, whose welfare is to be held prominently in view—in other words, from what standpoint is the problem to be attacked? If the former of these queries is answered in the negative, the problem remains a purely academic one—the study of causes and effects, and the recording of conclusions and data, without any telic purpose in view. No programs, schemes, or systems of reform can emanate from such a study. If answered in the affirmative, the problem then becomes one in applied sociology—perhaps the most complex and important that any modern nation has ever had to deal with. In regard to the second part of the above query, it is to be noted that there are four possible standpoints open to choice. First, that of the United States; second, that of the countries of source; third, that of the immigrants; fourth, that of humanity in general. There are possibilities of a different aspect of the problem from each of these viewpoints. Let us consider the two parts of this query in turn. There is a natural and deep-seated reluctance on the part of every careful and scientific student of sociology to advocate the regulation of any great human activity according to any man-made scheme or formula. The laws of nature seem so much safer a guide than any plan which, as Professor Summer says, some one has thought out in bed.[348] The _laissez-faire_ doctrine makes a great initial appeal. This probably accounts in large measure for its great vogue. The broad-minded and liberal man says, “What can be better or more just than to let each individual work out his own destiny in the way that seems to him best?” Particularly does such a tremendous movement as modern immigration inspire the student with feelings of reverential awe, rather than a desire to intermeddle. It is such a gigantic and complex thing, and cuts straight across all social relations with such an inclusive and unsparing sweep, that one can never know what the unknown factors are, nor what unforeseen and unexpected developments may arise. Certainly this seems one of the things that had better be left alone.