The whole history of Science illustrates this. We are all familiar with the way in which the predilections of religious feeling in the time of Copernicus and Galileo retarded the progress of astronomical Science. As long as people believed that a divine drama of redemption had been enacted on this earth alone, they naturally concluded that this earth was the centre of the universe, and refused to look at facts which contradicted their conclusion. When Galileo turned his newly-made telescope on Jupiter and saw it circled by its satellites, he saw in this an image of the Copernican system and of the planets circling round the central Sun; but when he asked others to share his observation and his inference, they would not. "O, my dear Kepler," he writes in a letter to his fellow astronomer, "how I wish we could have one hearty laugh together. Here at Padua is the principal Professor of Philosophy, whom I have repeatedly and urgently requested to look at the moon and planets through my glass; but he pertinaciously refuses to do so. What shouts of laughter we should have at this glorious folly!" And though we laugh at the folly of those before us, we do the same things ourselves to-day. Take the science of Political Economy. A revolution has taken place in that, almost comparable to the change from the geocentric to the heliocentric view in Astronomy. During the distinctively commercial period of the last 100 years, the leading students of social science, being themselves filled with the spirit of the time, have been fain to look upon the acquisition of private wealth as the one absorbing motive of human nature; and so it has come about that the economists, from Adam Smith to John Stuart Mill, have founded their science on self-seeking and competition, as the base of their analysis. To-day another series of economists coming to the front--their minds preoccupied with the great facts of Community of life and Co-operation--have discovered that Society is in the main an illustration of these latter principles, and have evolved a quite new phase of the science. It is not that Society has changed so much during this period, as that the altered point of view of the students of Society has caused them simply to fix their attention on a different aspect of the problem and a different range of facts.