Now the developments in modern science go back, through the Arabic thinkers, to ancient Greece; but the great advances that have been made date back scarcely three centuries. On the basis of the precise knowledge of physical relations which became available in mathematics, physics, mechanics, and chemistry the startling changes which have been crudely labelled the “industrial revolution” were carried through. If the essential relationship between the world of ideas and the world of action were ever in doubt, the industrial revolution, especially in its later phases, would be a final demonstration; for beneath the ostensible skyscrapers, subways, factories, telephone lines, and sewers of the modern industrial city lie the immaterial foundations of western physical science, laid down stone by stone in the remote, theoretic researches of Boyle, Faraday, Kelvin, Leibniz, and the rest of that great galaxy. With the far reaching effect of the idola of physical science it is hardly necessary to deal. Everyone realizes how dependent the advance in technology has been upon theoretic science, even though the scientist himself, as Kropotkin pointed out, is sometimes slow in admitting the debt of science itself to practical invention. The actual world of machinery is at present, it seems fair to say, a parasite upon this body of knowledge, and it would speedily starve to death if the host were annihilated. Science has provided the factual data by means of which the industrialist, the inventor, and the engineer have transformed the physical world; and without doubt the physical world has been transformed. Unfortunately, when science has furnished the data its work is at an end: whether one uses the knowledge of chemicals to cure a patient or to poison one’s grandmother is, from the standpoint of science, an extraneous and uninteresting question. So it follows that while science has given us the means of making over the world, the ends to which the world has been made over have had, essentially, nothing to do with science. Accordingly, as I have suggested, the idola of the Country House and Coketown and the National State, which were built up by literature and art, have given the effective direction to these transformations. So far, science has not been used by people who regarded man and his institutions scientifically. The application of the scientific method to man and his institutions has hardly been attempted.