_Peace_, which is a condensation or composite of all the rest and the end for which they all exist, has always been a fill and always must be until human actions become absolutely instinctive and unconscious, which they never can do until men have been acted upon and molded by habit by every stimulation possible to their environment. Reasoned acts are those which arise from stimulations, that are new or unusual to us, and new stimulations will continue to come as long as knowledge increases or continues to be pursued, or to be thrust upon us. If the accumulation of knowledge should stop, actions would finally become instinctive, and unconscious. This would be complete absence of misery, and also absence of happiness, but perfect peace. So the grade line of Peace is a dead level. Above it is the ragged line of misery always a great cut, and below it is the line of happiness always a fill, somewhat lighter than the cut above the line, and terminating in grade soon after it. I inquired of the Professor, the principle, upon which predictions of the future were worked out. He replied, that the principles were exceedingly simple, although the actual working out of any scheme of the future involved the consideration of such a vast number of details and conditions, as to render it a labor of magnitude. “Prediction,” said he, “is only past history, projected forward. If we know precisely what happened in the past, our knowledge will include the antecedent causes of the events. Events beget events, and they succeed each other as one generation succeeds another. Knowing the character and condition of one generation and the modifications that have been made in it by its environment, we have the principal data for estimating the character of its successor and so on. The principal uncertainty we encounter, is in the prediction of changes in the environment itself. Thus the invention of a self portable power like steam made the invention of railroads possible and the construction of railroads completely changed the environment of the succeeding generations. “Now it is difficult to forecast just what particular turn invention will take, but it is not impossible, because inventions constitute a race with generations one begetting another. Knowing all that is known to-day makes it possible to see what this knowledge will lead to to-morrow. The trouble is for one to know all that is known. As I have already mentioned, our own Lunarian history greatly aids us in our study of your future, for we have passed through an experience, which, while it is different from what yours has been or will be, is parallel and comparable with it. And making due allowance for the difference in physical structure of the two races and considering that we are 500,000 years older than you, we have only to consult our past in order to get your future, or something much like it, for many generations to come.”