We cannot, however, remain long content with this suggestion as to the principle concerned--namely, that progress is a natural and an assured result of change. The point is that catastrophe always means social change. There is not always progress. It is well to guard against confusion here. Change means any qualitative variation, whereas progress means "amelioration, perfectionment." The latter will be seen to depend on other things--the nature of the shock, the models presented, the community culture and morale, the stimulus of leaders and lookers-on. The single case of Galveston, Texas,[16] is sufficient to disprove the too optimistic hypothesis that the effects of catastrophies are uniform. Here a city lost heart by reason of the overwhelming flood, and in spite of superior commercial advantages was outgrown by a rival fifty miles away. At the same time the case of Dayton, Ohio, should be borne in mind. Here also was a flood-stricken city and she became "the Gem City of the West." The principle[17] thus appears to be that progress in catastrophe is a resultant of specific conditioning factors, some of which are subject to social control. [15] Thomas, _op. cit._, p. 18. [16] "It has one of the finest, if not the finest, ports in North America. In 1900 a great tidal wave swept over the city, causing enormous damage and loss of life. While the city has had a certain growth since that time, it has been far outstripped by Houston, Dallas, and other Texas cities."--Kirby Page, formerly of Texas, in a letter to the author. [17] Another principle is suggested for study by the following sentence in Ross' _Foundations of Sociology_ (p. 206): "Brusk revolution in the conditions of life or thought produces not sudden, but gradual changes in society." This might easily be elaborated. It is indeed this very thing which makes possible the hope of eventual social control over disaster-stricken cities, and the transmutation of seeming evil into tremendous good. And this is in addition to the many practical social lessons which we have already been intelligent enough to preserve, such as those of better city-planning, and a more efficient charity organization.