British historian Paul Johnson,[32] in analyzing the "heartless lovers of humankind," gives examples of people - among them many intellectuals - who represented strong beliefs and ideas but had no intention of getting acquainted with them through personal experience. Karl Marx inherited considerable sums of money and never had less than two servants. He was a ruthless exploiter of his familiy and friends, among them the socialist philosopher Friedrich Engels. he "was unwilling to do any on-the-spot investigating himself," and he never visited a factory; he had to rely solely on written reports and other types of knowledge through intermediaries.