61. But if one general requisite of independent and responsible life be a connection with the past, another is the possibility of action in the present. A living being must have in his frame the capacity of varied movement. He must possess an organisation in which there is the power of calling internal forces into play at irregular intervals dependent on his will. We cannot imagine life to be associated with a motionless mass or with a mass which moves in an invariable manner. The living being need not always be in motion, but he must retain the capacity of moving. He need not always be thinking, but he must retain the capacity of thought. He need not always be conscious, but he must retain the capacity of consciousness. To sum up—it thus appears that there are two general conditions of organised life. There must in the first place be an organ connecting the individual with the past, and in the next place there must be such a frame and such a universe that he has the power of varied action in the present. We particularly request our readers to keep well in mind these two propositions, since it is upon them that our argument will ultimately in great part be built. 62. We come now to a very important part of our inquiry. It will be necessary to discuss that which we term the _Principle of Continuity_, and desirable to begin by defining exactly what is meant by us when these words are used.[30] Let us introduce our definition by one or two illustrative examples. Take a particular problem of astronomy, for instance, and, beginning at the very commencement, let us suppose an early Egyptian or Chaldean astronomer to be observing the sun in the middle of summer. Day after day, for perhaps a week, he has noticed that this luminary rises over a certain place and sets over a certain other place, and he conceives that he has now obtained some definite information regarding the sun. His idea is, that the sun will go on always doing the same thing, and he therefore predicts to his fellows, who are less observant than himself, exactly where it will rise and where it will set. They join him in observing the luminary for a week or more, and the sagacity of our primeval astronomer is triumphantly vindicated: the sun is found doing as nearly as possible that which had been predicted of it.