Which parties were categorized as left-wing during the Weimar Republic?

The designation of certain political parties as left-wing during the Weimar Republic is primarily associated with their ideology and platforms. The Social Democrats and the Communists both aimed for a more egalitarian society, advocating for workers' rights and social reforms.

The Social Democratic Party (SPD) was the largest left-wing party and played a significant role in the early years of the Weimar Republic, supporting democratic governance and social reforms. On the other hand, the Communist Party of Germany (KPD) was even more radical, advocating for a revolutionary approach to establish a socialist state based on Marxist principles.

Both parties were opposed to the fascist and nationalist movements, which were characterized by their conservative and authoritarian ideologies. This ideological alignment with socialism and communism is what categorizes them as left-wing in the context of the Weimar Republic's political landscape. Consequently, the identification of the Communists and Social Democrats as left-wing is accurate.