“Ye are all fruits of one tree, the leaves of one branch, the flowers of one garden.” That is one of the most characteristic sayings of Bahá’u’lláh, and another is like it: “Glory is not his who loves his own country, but glory is his who loves his kind.” Unity—unity of mankind, and of all created beings in God—is the main theme of His teaching. Here again the harmony between true religion and science is evident. With every advance in science the oneness of the universe and the interdependence of its parts has become more clearly evident. The astronomer’s domain is inseparably bound up with physicist’s, and the physicist’s with the chemist’s, the chemist’s with the biologist’s, the biologist’s with the psychologist’s, and so on. Every new discovery in one field of research throws new light on other fields. Just as physical science has shown that every particle of matter in the universe attracts and influences every other particle, no matter how minute or how distant, so psychical science is finding that every soul in the universe affects and influences every other soul. Prince Kropotkin, in his book on Mutual Aid, shows most clearly that even among the lower animals, mutual aid is absolutely necessary to continued life, while in the case of man, the progress of civilization depends on the increasing substitution of mutual aid for mutual enmity. “Each for all and all for each” is the only principle on which a community can prosper. The Era of Unity All the signs of the times indicate that we are at the dawn of a new era in the history of mankind. Hitherto the young eagle of humanity has clung to the old aerie in the solid rock of selfishness and materialism. Its attempts to use its wings have been timid and tentative. It has had restless longings for something still unattained. More and more it has been chafing in the confinement of the old dogmas and orthodoxies. But now the era of confinement is at an end, and it can launch on the wings of faith and reason into the higher realms of spiritual love and truth. It will no longer be earthbound as it was before its wings had grown, but will soar at will to the regions of wide outlook and glorious freedom. One thing is necessary, however, if its flight is to be sure and steady. Its wings must not only be strong, but they must act in perfect harmony and coordination. As ‘Abdu’l-Bahá says:—“It cannot fly with one wing alone. If it tries to fly with the wing of religion alone it will land in the slough of superstition, and if it tries to fly with the wing of science alone it will end in the dreary bog of materialism.”