That forward movement divides it broadly from the older world; and the unity of the new is manifest in the universal spirit of investigation and discovery which did not cease to operate, and withstood the recurring efforts of reaction, until, by the advent of the reign of general ideas which we call the Revolution, it at length prevailed.[12] This successive deliverance and gradual passage, for good and evil, from subordination to independence is a phenomenon of primary import to us, because historical science has been one of its instruments.[13] If the Past has been an obstacle and a burden, knowledge of the Past is the safest and the surest emancipation. And the earnest search for it is one of the signs that distinguish the four centuries of which I speak from those that went before. The middle ages, which possessed good writers of contemporary narrative, were careless and impatient of older fact. They became content to be deceived, to live in a twilight of fiction, under clouds of false witness, inventing according to convenience, and glad to welcome the forger and the cheat.[14] As time went on, the atmosphere of accredited mendacity thickened, until, in the Renaissance, the art of exposing falsehood dawned upon keen Italian minds. It was then that history as we understand it began to be understood, and the illustrious dynasty of scholars arose to whom we still look both for method and material. Unlike the dreaming prehistoric world, ours knows the need and the duty to make itself master of the earlier times, and to forfeit nothing of their wisdom or their warnings,[15] and has devoted its best energy and treasure to the sovereign purpose of detecting error and vindicating entrusted truth.[16] [Sidenote: INTERNATIONAL IDEAS] [Sidenote: MEMORABLE MEN] [Sidenote: INDEPENDENT MINDS]