Frederick Engels, Karl Marx
[Political philosopher, b. 1818, Barmen, Germany, d. 1895, London.]
[Political philosophers, b. 1818, Trier, Germany, d. 1883, London.]
If in all ideology men and their circumstances appear upside-down as in a camera obscura, this phenomenon arises just as much from their historical life-process as the inversion of objects on the retina does from the physical life-process. 
