Space is the expansion and extension of the forces of nature into the infinite. Time is the limitation of this activity. Without space no object could arrive at completion. Without time the subject would be eternal. These are the two counteracting elements. The one, space, is positive--the other, time, negative. Time is either relative or absolute. If relative, it can be measured by an ascertained succession of events. If absolute, it becomes measurable by years. In both we can trace a gradual and successive development of artistic forms. In general, time relative, with its succession of products, is more reliable than time labelled with voluntary and more than doubtful dates. For instance, we cannot measure the periods of the formation of the earth’s crust by years, and still we are perfectly convinced that the _tertiary_ formation could not have taken place before the _primary_; thus we are justified in assuming that the iron period must have succeeded the stone or bronze period; bronze instruments never being found with iron handles, whilst iron blades have ornamented wooden or bronze handles. Man naturally scarcely ever uses the worse material for a practical purpose when he has once found a better one; but he will use the softer material as a means of ornamentation. That we have plenty of ‘survivals’ in art, as well as in nature, does not in any way militate against the strict logic of facts. The lowest forms of animals have mostly survived (like the lowest forms of ornamentation), yet no one can doubt or deny the gradual and systematic development of the vegetable and animal kingdoms. If we find no fragments of pottery in Australia, New Zealand, or the Polynesian islands, we cannot assume that a grand and powerful civilisation has perished there, leaving no traces behind. In finding different kinds of pottery, gradually improving even in the quality of the material--the clay being first unwashed, then mixed with grains of quartz and felspar, next carefully washed, then sun-baked, then fire-baked; first hand and then wheel turned, and at last glazed, unornamented or ornamented--we cannot assume that the order was inverted, and that man first ornamented glazed pottery, which he turned out on the wheel, and then went back to unwashed clay and hand-made pottery. The ‘degeneration theory’ has exploded as entirely as the geocentric and anthropocentric theories have vanished. We know that man, like flowers, trees, rocks and animals, is the product of the combined forces of nature and the influences of climate and food, and that his religious, social, and political conditions are closely reflected in his art. As little as our globe is the centre of the universe, or man the centre of creation, so little did art or science spring at once perfectly armed, provided with spear and shield, from Jupiter’s head like blue-eyed Athene. In a certain sense art and science are both of divine origin,