After his graduation he began studying medicine in Freiburg im Breisgau, Bonn, and finally Munich, where, in greater conformity with his real interests, he turned to literature, philosophy, and psychology.

His plans of habilitation at the University of Dresden were abandoned in the face of continuing public outrage over the influence in academia of Jews, socialists, and feminists.

[3] In January 1910 he created a literary scandal with a vicious attack on the critic Samuel Lublinski and his Bilanz der Moderne (1904), in a piece published in Die Schaubühne filled with "Jewish jokes" and gibes about Lublinski's appearance; it drew strong condemnation from Thomas Mann, who returned the insults by calling Lessing a "disgraceful dwarf who should consider himself lucky that the sun shines on him, too."

At this time he wrote his famous essay Geschichte als Sinngebung des Sinnlosen ("History as Making Sense of the Senseless").

From 1923 he was highly active in public life, publishing articles and essays in Prager Tagblatt and Dortmunder Generalanzeiger, and quickly became one of the best-known political writers of Weimar Germany.

In 1925 he drew attention to the fact that the serial killer Fritz Haarmann had been a spy for the Hanover police, and this resulted in him being excluded from covering the trial.

In the same year he wrote an unflattering piece on Paul von Hindenburg, describing him as an intellectually vacuous man who was being used as a front by sinister political forces: This article earned him the enmity of nationalists, and his lectures were soon disrupted by anti-Semitic protestors.

On 30 January 1933, the Nazi Party entered government and in February, after the suppression of the Das Freie Wort congress, Lessing prepared to leave.