Philosophers, Ernst Bloch said, adapting a joke by Thomas Mann, are people for whom thinking is more difficult than for others, because in them the sting of wonder and amazement is more developed. From 1949 until his forced retirement in 1956, Bloch gave lectures on the history of philosophy in Leipzig. "The lecture hall had a 'red glow'," admitted even one of those who condemned him in the GDR. This edition brings together Bloch's lectures on the history of philosophy from antiquity to the 19th century in four volumes. The presentation of ancient and modern philosophy in volumes 1, 3, and 4 is primarily based on transcribed audio recordings from the years 1952 to 1956, while volume 2 on the Middle Ages and Renaissance is based on the final version edited by Bloch himself.