What did pure marxists believe about capitalism:

1. Marxists believe they knows laws of history, 2. in other words they believe they have access to deeper meaning (religious stance, isn´t it?)  of history, 3. in other words they believe they know where all events go (really inflated stance). In the history of events capitalism (let alone what they mean by this word) is a decadent phase of history that will be overcome. Capitalism is - by the nature eliminated - and communism is (by the nature of the history) destined to be final form of social order.

Explanation: Marx had a prophetic aspect of the personality and this part of his (and his work) was so attractive to those who felt "victimized" that believed his prophecies. This is one of the factor why there were/are Marxists Marx´s thought is seductive because of its promises.

a memoir is the correct answer