  To twentieth philosophy, Mach is best known as a positivist who influenced Logical Positivism, a philosopher of physics who influenced Einstein, and an empiricist who denied the reality of atoms. None of this is incorrect, but to understand Mach as limited to physics is a huge mistake. Mach’s influence upon physics and its philosophy was enormous; the mistake has been to not understand the roots of Mach’s ideas, a mistake which took place early in the twentieth century as a new brand of positivism/empiricism entered the scene (one which turned away from the life sciences as the scientific driving force of positivist epistemology and focused on the new developments in the foundations of physics and logic). This encyclopedia has several entries on the history and philosophy of physics (see links below) which detail Mach’s ideas, contributions, and influences (in particular, his famous critique of Newtonian Absolute Space and Time, as well as his relationship to Einstein). What follows is a placement of his ideas within the context of his larger thought.