In dwelling on the performances of San Francisco after the great disaster of 1906, and in pointing out that material advancement is not dependent on the moral status of a community there is no desire to convey the impression that profit is derived from the pursuit of vicious courses.
The parasite never contributes to the growth of the thing on which it fastens, but on the other hand the purest of motives, the best of intentions and the most perfect of laws unaided cannot promote the growth of a city. That depends entirely on the sagacity and energy of its people. Urban expansion is a purely material phenomenon, and whether we like to recognize the fact or not the flower of spirituality seems to grow most luxuriantly in the muck heap of wealth produced in the commercial struggle.
Virtue is the antithesis of vice, and the worst forms of the latter are those which human greed calls into existence. But exaggerated human desire seems as necessary for the preservation of the race as the fertilizing element is to soil productivity. And like the agriculturist who is called upon to deal with the problem of providing for the subsistence of his kind, society must make up its mind that its struggle with parasitic enemies will be incessant. There are times when the horticulturist is compelled to cut down and destroy trees to prevent the spread of some infectious disease, but he rarely extends his precautions to the extirpation of all trees, as he would have to do if he wished to completely eradicate the evil he attacks, an end which could only be accomplished by the destruction of the fertilizers which promote productivity.
Source: Chapter LXVI: The Summing Up of the Achievements after the Fire in San Francisco a History of the Pacific Coast Metropolis – Volume II — American County Histories: California – Upper image is from the book.