Is this selection, we may ask, only a device on the historian's part to facilitate our comprehension, or is it a genuine characteristic of the time process itself? Does the historian read purpose into history or does he find it there? It may assist in answering such questions to observe that if selection is a device of the historian, it is one to which he is compelled. Without it history is unintelligible. Unless we understand events and circumstances as contributing to a definite result and contributing in different measures, we do not understand them at all. The Magna Charta, the British Constitution, the Tower of London, the River Thames, the mines of Wales, the plays of Shakespeare--all these things and things like them are for us quite unintelligible if they illuminate no career or illustrate no specific movements to which they have particularly contributed. Selection is, consequently, not a device which the historian has invented; it is imposed upon him by his own purpose to preserve the memory and promote the understanding of what has happened. The procedure of the historian is not arbitrary, but necessary. It is imposed upon him by the character of the facts with which he deals. These facts are movements from the possible to the actual and are helped and hindered by other such movements. An historical fact is not only spread out in space and exists equally with all its contemporaries at an assignable place in reference to them, it also persists in time, comes before and after other persisting facts, and persists along with others in a continuance equal to, or more or less than, theirs. In a figure we may say, facts march on in time, but not all at the same speed or with the same endurance; they help or impede one another's movement; they do not all reach the goal; some of them turn out to be leaders, others followers; their careers overlap and interfere; so that the result is a failure for some and a success for others. The march is their history. This is figure, but it looks like the fact. Simple illustrations may enforce it. The seeds which we buy and sow in the spring are not simply so many ounces of chemical substances. They are also so many possible histories or careers in time, so many days of growth, so much promise of fruit or flower. Each seed has its own peculiar history with its own peculiar career. The seeds are planted. Then in the course of time, soil and moisture and atmosphere and food operate in unequal ways in the development of each career. Each is furthered or hindered as events fall out. Some careers are cut short, others prosper. Everywhere there is selection. Everywhere there is adaptation of means to ends. The history of the garden can be written because there is a history there to write.