Sartre demonstrates this in Being and Nothingness; Bachelard also says it in his works on Earth, Air, and Water: psychoanalysts believe that man's quintessential truth lies in his relation to his own body and that of others like him within society; but man has a primordial interest in the substance of the natural world surrounding him that he attempts to discover in work, play, and all experiences of the 'dynamic imagination'; man seeks to connect concretely with existence through the whole world, grasped in all possible ways.