exploitation of child labour, the rampant alcoholism, the "smoky factory buildings" and the red-dyed Wupper river--and linked this misery directly to the religious hypocrisy of the Pietist factory owners. The publication of the Letters caused a severe conflict with his parents and established the basis for his later separation from them.

During this time, Engels underwent a profound intellectual and spiritual transformation. Dissatisfied with the "narrow spiritualism"