 anarchism |  essential vs. accidental properties |  Frege, Gottlob |  Galileo Galilei |  Kuhn, Thomas |  Lakatos, Imre |  liberalism |  logic: inductive |  -->logical positivism--> |  Mach, Ernst |  Marxism, analytical |  meaning, theories of |  Mill, John Stuart |  Nietzsche, Friedrich |  Popper, Karl |  postmodernism |  Principia Mathematica |  quantum mechanics |  rationalism vs. empiricism |  realism |  relativism |  scientific method |  scientific realism |  -->social democracy--> |  Vienna Circle |  Wittgenstein, Ludwig 