We might well pause at this point to consider the philosophy of revolutions. It would be an interesting study to investigate the efficient or radical causes of these singular phenomena of God's providence--these crises in history, when 'the fountains of the great deep are broken up,' and the experience of centuries is crowded into the limits of a single year, and we see the old landmarks all swept away before the overwhelming tides of a new era. Then it is that precedents avail us nothing, and we are driven to lay hold of those principles of justice and right which are alone eternal. For in the storm and wreck of revolution those principles are our sure beacon lights, shining on, like the stars, forever. Thus philosophizing, the question would be: Have revolutions a fixed law? Is there a recurring sequence in the mighty 'logic of events,' that will enable us to define a formula for the revolutions of systems in society? So science has demonstrated a law for the revolutions and changes of systems of worlds in infinite space. Or, are the revolutions of history, like the volcanic disturbances of our planet earth, in a sort, abnormal? They seem to come, like the _deus ex machina_ of the Roman poet, to cut the Gordian knots that perplex statesmen and bewilder nations. The affairs of men get so tangled up sometimes, that to prevent anarchy and chaos, God sends revolutions, which sweep away the effete institutions and old, worn-out systems, to replace them with new and living systems. And thus there is a perpetual genesis, or new creation, of the world. Let any one read Carlyle's vivid description of the badness of the eighteenth century, 'bad in that bad way as never century before was, till the French Revolution came and put an end to it,' and he will understand something of this question of revolutions. It suggests the old scholastic dispute of the free agency of man, and looks as though, granting that freedom, it were, after all, too great a gift for us. For history seems to teach, as its one grand lesson, confirming, as always, the revelation in Christ, that men cannot take care of themselves; and that God leaves them to their own ways long enough to satisfy them that human agency is inadequate to solve the question of reform, and then, when the times are ripe, He takes the reins into His own hand, and starts society anew. It is the patient process of education by centuries, or by ages--only to be made perfect in the millennial age. So it is that the world moves. It moves by the free agency of man, kept in its balance by the guiding hand of God. I. THE VEXED QUESTION OF THE NEGRO.