He attended school with the sons of officers and businessmen in Berlin and went on to university, but broke off his studies in 1889 without taking his degree.
His parents had hoped he would enter the now faltering family business, but he chose instead to begin working as a news agency reporter. Two years later he obtained a position with a newspaper in Frankfurt. His new iob coincided with an upsurge of the Social Democrats to whom Eisner, a rebel since his school days, was drawn. It also sparked in him an interest in philosophy and he published his first work, a book about Nietzsche. He had mixed feelings about Nietzsche, but concurred with his criticisms of elitist German institutions, among them universities, which he himself once described as “penitentiaries for future bureaucrats.”
In 1892, his work took him to Marburg, where he studied with Hermann Cohen and began to develop a personal philosophy that combined Kant with socialism. His journalism gave him opportunity to use his caustic wit to good effect in criticizing the current political trends. On one occasion, however, a criticism of the kaiser entitled “Ceasar Mania” landed him in prison for nine months. Although his jail term disqualified him for the position he had been offered at Marburg University, his notoriety led to his appointment as editor of the Social Democrats’ newspaper, Vorwärts. Interparty disputes, and his own propensity to alienate every faction of the party led to his dismissal in 1907, at which time he left Prussia for Bavaria. He worked for a time in Nuremburg, then moved to Munich, where he continued to work as a journalist. When, in August 1914, he used his column to criticize German aggression, he again lost his job. He became known as somewhat of an eccentric who wandered around Munich with a knapsack of books or provisions on his back.
In 1916, he founded, at a tavern in Munich, a weekly discussion group with an antiwar slant. Although the authorities took little notice of this activity, he soon had audiences of some one hundred listeners. At least part of the attraction was evidently his own outlandish appearance, a deliberately effected look of etherealism. In 1917 he joined the Independent Social Democratic party and became its leader.
In 1918, he was arrested as a leader in the anti-war strikes and imprisoned foreight and a half months without trial or charge. Upon his release he immedately became involved in the bloodless revolution which overthrew the Bavarian monarchy, proclaimed the Bavarian Republic, and demanded peace.
His collected works were published in 1919.