It was only under the influence of some external terror--a plague, a desolating war, an imminent peril to the nation--that the religious sense, deadened by worldliness and selfish philosophy, made itself felt. At such seasons whole cities rushed headlong into fierce revivalism, while men of violent or profligate lives saw visions, and betook themselves to penance. Cellini's Memoirs are, on this point, a valuable mirror of the age in which he lived. It is clear that his ecstasies of devotion in the dungeons of S. Angelo were as sincere as the fiery impulses he obeyed with so much complacency. Passionate and worldly as men of Cellini's stamp might be, they could not shake off the associations that bound them to the past. The energy of their intense individuality took turn by turn the form and colour of ascetic piety and Pagan sensuality; and at times these strong contrasts of emotion seemed bordering upon insanity. Ungovernable natures, swayed by no fixed principle, and bent on moulding the world of thought afresh to suit their own desires, became the puppets of astrological superstition, the playthings of mad lust. Much that appears unaccountable and contradictory in the Renaissance may be referred to this imperfect blending of ecclesiastical tradition and idealised Paganism in natures potent enough to be original and wilful, but not yet tamed from semi-savagery into acquiescence by experience. Experience came to the Italians in servitude beneath the heel of Spain. The confusion of influences, classical and mediæval, Christian and Pagan, in that age is not the least extraordinary of its phenomena. Even the new thoughts that illuminated the minds of great discoverers, seemed to them like reflections from antiquity; and while they were opening fresh worlds, their hearts were turned toward the Holy Land of the Crusades. Columbus and Copernicus, the two men who did more than any others to revolutionise the mental attitude of humanity, appealed to their contemporaries on the strength of texts from Aristotle and Philolaus. Conscious that the guesses of the Greek cosmographers had stimulated in themselves that curiosity whereby they made the motion of the earth a certainty, and found a way across the waves to a new continent, these mighty spirits forgot how slight in reality was their debt to the inert speculators of the classic age. The truth was that in them throbbed a force of enterprise and conquering discovery, a spirit of exploration resolute and hardy, denied to the ancients.