There is a theory which has much currency nowadays, that the great man, being a product of his century, exerts an influence upon his age which is but vanishing, compared to the influence which the age exerts upon him. The great man is, according to this view, personally of small account, except in so far as the tendencies and ideas which are fermenting in the age find their expression in him. He does not so much shape the events as he is shaped and moulded by them. There is scarcely a hero to be found in all the annals of history who is better qualified to refute this theory than the Swedish king, Gustavus Adolphus. It would be futile to assert, of course, that he was an isolated phenomenon, who sprang like Jonah's luxuriant gourd out of the arid sands of the desert. No, he had deep and intricate roots in the past of his race and in the soil of his fatherland. But yet, how far are all the influences which we can trace, from accounting for the forceful energy, the clear-sighted sagacity, and the dominant genius of the man! As far as we can judge at this distance, his personality was the mightiest element that entered into the denouement of that bloody world-drama, the Thirty Years' War. Had he been other than he was, had he been a man of less heroic mould, it would seem that Protestantism must have perished in Central Europe, or been confined, at least, to England and the Scandinavian North. The rights of conscience and individual judgment, for which Luther and his co-reformers had fought so valiantly, would then have succumbed to the power of authority, as embodied in the Papacy and the Catholic League; and Germany, after its mighty effort at release, would have lapsed back into the Middle Ages. To few men the opportunity is offered to exercise such a far-reaching influence upon the history of mankind; but fewer still are those who see its full significance, and seeing it, seize it, and without one look behind march into the storm and stress of world-shaping events.