The last of the great schoolmen, William of Ockham, called the "Invincible Doctor," suffered imprisonment and exile on account of his works. He was born at Ockham in Surrey in 1280, and, after studying at Oxford, went to the University of Paris. He lived in stirring times, and took a prominent part in the great controversies which agitated the fourteenth century. Pope John XXII. ruled at Avignon, a shameless truckster in ecclesiastical merchandise, a violent oppressor of his subjects, yet obliged by force of circumstances to be a mere subject of the King of France. The Emperor Ludwig IV. ruled in Germany in spite of the excommunication pronounced against him by the Pope. Many voices were raised in support of Louis denouncing the assumptions of the occupant of the Papal See. Marcilius of Padua wrote his famous _Defensor Pacis_ against Papal pretensions, and our author, William of Ockham, issued his still more famous _Defence of Poverty_, which startled the whole of Christendom by its vigorous onslaught on the vices of the Papacy and the assumptions of Pope John. The latter ordered two bishops to examine the work, and the "Invincible Doctor" was cast into prison at Avignon. He would certainly have been slain, had he not contrived to effect his escape, and taken refuge at the court of the German emperor, to whom he addressed the words, "_Tu me defendas gladio, ego te defendam calamo_." There he lived and wrote, condemned by the Pope, disowned by his order, the Franciscans, threatened daily with sentences of heresy, deprivation, and imprisonment; but for them he cared not, and fearlessly pursued his course, becoming the acknowledged leader of the reforming tendencies of the age, and preparing the material for that blaze of light which astonished the world in the sixteenth century. His works have never been collected, and are very scarce, being preserved with great care in some of the chief libraries of Europe. The scholastic philosophy of the fourteenth century, the disputes between the Nominalists and the Realists, in which he took the part of the former, the principle that "entities are not to be multiplied except by necessity," or the "hypostatic existence of abstractions," have ceased to create any very keen interest in the minds of readers. But how bitterly the war of words was waged in the fourteenth and fifteenth centuries! And it was not only a war of words; one who witnessed the contests wrote that "when the contending parties had exhausted their stock of verbal abuse, they often came to blows; and it was not uncommon in their quarrels about _universals_, to see the combatants engaged not only with their fists, but with clubs and swords, so that many have been wounded and some killed." These controversies have passed away, upon which, says John of Salisbury, more time had been wasted than the Caesars had employed in making themselves masters of the world; and it is unnecessary here to revive them.