My Manifesto: The Incoherent Ramblings of a Madman

"Just as Darwin discovered the law of development or organic
nature, so Marx discovered the law of development of human history:
the simple fact, hitherto concealed by an overgrowth of ideology, that
mankind must first of all eat, drink, have shelter and clothing,
before it can pursue politics, science, art, religion, etc.; that
therefore the production of the immediate material means, and
consequently the degree of economic development attained by a given
people or during a given epoch, form the foundation upon which the
state institutions, the legal conceptions, art, and even the ideas on
religion, of the people concerned have been evolved, and in the light
of which they must, therefore, be explained, instead of vice versa, as
had hitherto been the case." - An exert by Engels talking of Marx after his death.