Every machine must be perfect of its sort. It is essential to a locomotive that it can reverse its movement, and run backward and forward with equal celerity. The builder of the mind found it not less needful that it should have retroaction, and command its past act and deed. Perception, though it were immense and could pierce through the universe, was not sufficient. Memory performs the impossible for man by the strength of his divine arms; holds together past and present, beholding both, existing in both, abides in the flowing, and gives continuity and dignity to human life. It holds us to our family, to our friends. Hereby a home is possible; hereby only a new fact has value. Opportunities of investment are useful only to those who have capital. Any piece of knowledge I acquire to-day, a fact that falls under my eyes, a book I read, a piece of news I hear, has a value at this moment exactly proportioned to my skill to deal with it. To-morrow, when I know more, I recall that piece of knowledge and use it better. The Past has a new value every moment to the active mind, through the incessant purification and better method of its memory. Once it joined its facts by color and form and sensuous relations. Some fact that had a childish significance to your childhood and was a type in the nursery, when riper intelligence recalls it means more and serves you better as an illustration; and perhaps in your age has new meaning. What was an isolated, unrelated belief or conjecture, our later experience instructs us how to place in just connection with other views which confirm and expand it. The old whim or perception was an augury of a broader insight, at which we arrive later with securer conviction. This is the companion, this the tutor, the poet, the library, with which you travel. It does not lie, cannot be corrupted, reports to you not what you wish but what really befel. You say, “I can never think of some act of neglect, of selfishness, or of passion without pain.” Well, that is as it should he. That is the police of the Universe: the angels are set to punish you, so long as you are capable of such crime. But in the history of character the day comes when you are incapable of such crime. Then you suffer no more, you look on it as heaven looks on it, with wonder at the deed, and with applause at the pain it has cost you. Memory is not a pocket, but a living instructor, with a prophetic sense of the values which he guards; a guardian angel set there within you to record your life, and by recording to animate you to uplift it. It is a scripture written day by day from the birth of the man; all its records full of meanings which open as he lives on, explaining each other, explaining the world to him and expanding their sense as he advances, until it shall become the whole law of nature and life.