Friedrich Schiller’s dramatic works are often divided into three periods: early, middle, and classical. Don Carlos, which took Schiller four years to write and was completed in 1787, is the single play representing the middle period. It is a melodramatic high tragedy written in blank verse, which combines complicated political ideas with a story of doomed love.

In the course of writing Don Carlos, Schiller’s ideas about the characters changed. Because the first three acts were published in Die Thalia between 1785 and 1787 as they were completed, the playwright felt he had to resolve this story line, despite his preference. He would have reworked the play quite differently and created characters more suited to his new ideas had the first acts not already been in the hands of the public. Schiller said of Don Carlos, “The parts that first attracted me began to produce this effect in a weaker degree . . . Carlos himself lost my favor, perhaps for no other reason than because I had become his senior, and Posa replaced him. I commenced the fourth and fifth acts with quite an altered heart.” The inconsistencies in Don Carlos are the result of this change of course. Later in his life, Schiller was extremely critical of Don Carlos. In his Letters upon Don Carlos, he wrote, “in the first (three) acts I aroused expectations that the last do not fulfill.” In the final two acts, Posa does not act in accordance with his earlier course. Initially, he proclaims his loyalty to Carlos; then he seems to ally himself with the king. Probably he could have used that friendship to support his goals of social justice, but when he ruins that possibility the plans for rebellion are destroyed, and all the while Carlos remains in the dark about the greater duties that drive Posa. In the first three acts, Posa is a heroic idealist; in the next acts, he is an unjustified maniac. Even his death, which he feels is purely sacrificial, does not help Carlos, his own greater cause, or anyone else.

Don Carlos was a public success, but critics pointed out some flaws. Schiller’s research into the Spanish monarchy of the sixteenth century had shown him several different ways to interpret the same historical moment. He had used Louis-Sébastian Mercier’s factual account Portrait of Phillipe II (1785), which he translated into German, and for some details he drew on Robert Watson’s History of the Reign of Phillipe II (1778). Much of the story line for Don Carlos, however, comes from César Vichard Saint-Réal’s eighty-page Dom Carlos, Nouvelle Historique (1672), the least factual of his sources, and as a result Schiller’s play may actually contain very little, if any, factual or historical matter.

The most important theme in the play is that of realism versus idealism. Philip represents a harsh and conservative realist who is interested in people only to the extent that they are useful to him; he is not at all interested in improving his subjects’ well-being. Posa represents an idealist who strives to improve conditions for all people and to liberate them to a higher plane of existence. One of the most famous lines of this play, in the midst of the most powerful of its compelling scenes, is Posa’s statement to the king, “O Give us freedom of thought.” In this scene, incidentally, Schiller the philosopher overruns Schiller the poet. In presenting what amounts to a treatise on government, the action and the love story are suspended. The conclusion of the third act reflects the change that...