Though anti-Semitism was endemic in France in the 1890s, historians still differ on the extent to which Alfred Dreyfus was deemed a traitor because he was a Jew. In the months prior to his arrest, the rabble-rousing anti-Semitic broadsheet La Libre Parole, edited by Edouard Drumont, had campaigned against the admission of Jews into the officer corps of the French army. Most French Jews came from Alsace; their mother-tongue was a Germanic dialect (Dreyfus himself spoke with a German accent); and a number of German Jews had become naturalised Frenchmen: the politician Joseph Reinach, an early supporter of Dreyfus, was the son of a German banker. Other Jewish bankers like the Rothschilds, or merchants like the Ephrussis, were of foreign provenance. To French nationalists, such Jews were not "true Frenchmen from France" and so could not be trusted with the defence of the realm.

 

It was also widely believed by many French Catholics, particularly the lesser clergy, that their Jewish fellow-citizens, heirs to a Talmudic enmity towards the Catholic Church, had combined with the French atheists, Protestants and Freemasons to support the anti-clerical programmes of successive Republican governments —  in particular, the assault upon Catholic education. Sceptics such as Barrès and atheists like the young Charles Maurras shared this view. Catholicism was integral to French identity and the army was the last bastion of Catholic France — immune, unlike the politicians, from the corrupting influence of Jewish and Protestant high finance. The campaign to free Dreyfus was therefore perceived both as an attempt by the Jewish "syndicate" to save one of their own, and as a conspiracy to discredit the "holy of holies" of the true France, the Army High Command.

The case for a revision rested on a judgment that while the handwriting of the traitor on the compromising document filched from the German embassy may have been similar to that of Dreyfus, it was identical to that of Esterhazy. "Take from the street a passing child," wrote Zola, "and show him the two samples: ‘It's the same gentleman who wrote the two.' He doesn't need experts — the fact that the two are identical is obvious for all to see!" However, neither the child in the street nor Zola were expert graphologists who, on this question, had taken divergent views. Moreover, successive Ministers of War had insisted that there was other, incontrovertible evidence that proved the guilt of Dreyfus which, for reasons of national security, could not be made public.

 

In the event, it turned out that these ministers were the dupes of French military intelligence. The secret documents that supposedly proved the guilt of Dreyfus were either forged or non-existent.  However, this was by no means clear at the time. The issue was whether or not one trusted the Army High Command and here, another passionately held prejudice came into play — by no means comparable to anti-Semitism but equally virulent. "Le cléricalisme, voilà l'ennemi," Léon Gambetta had said in 1876, and for much of the last three decades of the 19th century anti-clericalism was the unifying ideology on the Left. To the Dreyfusards, the French officer corps was dominated by an aristocratic, Jesuit-educated elite; and the conspiracy against Dreyfus was directed by the former headmaster of a Jesuit crammer, Père du Lac.

In reality, only one of the officers at the heart of the Dreyfus Affair had been educated by the Jesuits, and the prime mover, General Mercier, was a bona fide republican with an English and Protestant wife. A Jesuit conspiracy was as much a symptom of paranoia on the republican Left as the belief in a Jewish "syndicate" was on the nationalist Right. Nevertheless, Dreyfus was innocent and the anti-Dreyfusards have been punished for being wrong. As Maurice Barrès foresaw, "If Dreyfus and his friends become historians and write textbooks, we shall be villains in the eyes of posterity."