In the eyes of dialectical philosophy, nothing is established for all times, nothing is absolute or sacred.
Karl MarxNature is man's inorganic body -- that is to say, nature insofar as it is not the human body. Man lives from nature -- i.e., nature is his body -- and he must maintain a continuing dialogue with it is he is not to die. To say that man's physical and mental life is linked to nature simply means that nature is linked to itself, for man is a part of nature.
Karl MarxOne of the most difficult tasks confronting philosophers is to descend from the world of thought to the actual world.
Karl Marx