In Der Satz vom Widerspruch I had preached the primacy of practice
over mere facts and concluded that the question ›What is Truth?‹ could be
resolved by finding out what kind of people were able to get at the truth.
In other words, what had to be done was to discover a disinterested truth-
bearing section in society
. This was, as I said then, the revolutionary
proletariat represented by the C.P. trained in scientific socialism.
[The Memoirs of A Modern Gnostic, Part I, p. 36]

Der Marxismus dagegen behauptet,
daß bestimmte Gruppen, nicht weil sie überhaupt,
sondern weil sie in einer näher zu bestimmenden Weise interessiert sind,
weder ein Interesse an noch eine Möglichkeit zur Wahrheit haben,
während andere Gruppen wiederum, nicht trotz, sondern wegen
ihrer besonderen Gruppeninteressen ein Interesse an
der Wahrheit und die Möglichkeit zu ihr haben.
[Der Satz vom Widerspruch: #321 Zum Begriff der Ideologie]

In The Scientific Method of Thinking I spelled this out for practical Englishmen
by saying that mankind was doomed unless could apply to the ordering of society
the same kind of scientific method
which had led to all these discoveries in
the natural sciences and that dialectical materialism provided that method.
My later views can easily be deduced from this starting point.«
[The Memoirs of a Modern Gnostic, Part I, p. 36]