When the great humanist Erasmus of Rotterdam eulogized his friend Albrecht Dürer, he compared him to Apelles, the ancient Greek painter whose name was a byword for artistic prowess. "Apelles was assisted by colors," wrote Erasmus, "but Dürer, though admirable also in other respects, what does he not express in monochromes, that is, in black lines? … And is it not more wonderful to accomplish without the blandishments of colors what Apelles accomplished with their aid?"

Nearly 500 years after Erasmus, those black lines are as powerful as ever. Contemplating one of Dürer’s woodcuts or engravings, we are amazed and nearly overwhelmed. This is not an art that seeks to conceal itself; there is a density here, not only of line and shading but of thought. Every square inch vibrates with power and significance. Within the ruled borders of the page, vast spaces open out, and an equally vast inner space of ideas and symbols comes into view as we study the iconography.

Of all his prints—some 350 woodcuts and 105 intaglios—perhaps the richest in rewards for the eye and the mind are the three engravings on copper traditionally known as the Meisterstiche (master engravings), made during the years 1513 and 1514. Dürer was then at the height of his powers as an artist and financially successful enough that he could set himself his own themes rather than execute commissions for patrons or illustrate Biblical stories for devotional use. Dürer had already become famous for his widely published series of woodcuts of the Passion of Christ and the Revelation of St. John, which elevated a quotidian form to the highest level of art. He had appealed deeply to the popular mind, and his prints were tacked on walls all over Europe. Now, with these three large-format works—each approximately 10 by 7 inches—the Nuremberg master was ready to make a more recondite statement, deeply personal and philosophical.

The first of the engravings he completed is usually called "The Knight, Death and the Devil," though Dürer himself referred to it simply as the "Reuter," or rider. A stern and dignified man in armor, seated on a magnificent horse and accompanied by a faithful hunting dog, strides through a craggy forest landscape with a lance over his shoulder and a sword at his side. In the distance is a castellated city on a high hill. Alongside him, on a broken-down nag with its head hanging rides Death, portrayed as a decomposing, still-bearded corpse wearing a crown through which snakes are crawling. In his hand is an hourglass, and a memento mori skull lies on the ground nearby. Behind the rider, shadowing him, is the Devil, not a suave Satan but a scaly, horned monster with goat legs and a face that looks like a cross between a boar and a goat. In the presence of these supernatural entities the rider appears utterly serene, neither angry nor afraid. The threat of death and the temptations of the Evil One disturb him not at all, and indeed, these two are shown as ineffectual and almost comical monsters rather than as uncanny inspirers of terror. They are rendered powerless by the rider’s dignity and firmness of purpose as he rides right past them.

The identity of the rider has been endlessly speculated upon. In Dürer’s day he was seen variously as Martin Luther, Savonarola, Pope Julius II and even the soldier of fortune Franz von Sickingen. In the 19th and 20th centuries, nationalistic interpretations became common; essentially, the rider was Germany. During the Nazi period, Nuremberg mayor Willy Leibel gave Hitler a copy of the print, calling the Führer the "fearless and flawless knight." A few years earlier, a rabbi in the same city, Max Freudenthal, had given a sermon in which he interpreted the knight as the Jewish people braving anti-Semitism. According to the great art historian Erwin Panofsky, author of a seminal work on Dürer, the rider is most likely a personification of Erasmus’ miles Christianus (Christian soldier), a peaceful warrior for truth and faith. Stylistically speaking he is a paragon of the Northern Renaissance; the armor is stiffly Late Gothic, while the horse is modeled on Italian equestrian statues and the rider’s proportions are precisely set by the canon of classical antiquity.

Going from this rugged scene to the next engraving, "St. Jerome in His Study," from 1514, we feel a comforting sense of warmth. Now we are in a cozy room with a coffered wooden ceiling, bathed in what must be a golden light streaming in through round-mullioned windows. The way Dürer has represented this light by means of engraved lines is nothing short of marvelous, as is the tactile sense of the wood’s grain that he conveys. More light emanates from the head of the scholarly saint in the form of a halo as he bends over his writing desk. There is a skull here, too, on a shelf, but in these surroundings it looks anything but ominous; beneath it on the floor are the saint’s bedroom slippers. In the foreground a dog and a cat lie sleeping—only this cat is a lion, traditionally associated with St. Jerome, who tamed him.

The art historian Friedrich Lippmann observed that although the master engravings are not actually a formal suite, they represent the three kinds of virtue as understood by medieval scholasticism: moral, theological and intellectual. If the Rider is moral virtue, St. Jerome, the great translator of the Holy Scriptures into Latin, is certainly theological virtue.