that ordinary experiences provide intuitively certain assurance of the existence of the self, of real objects that could be seen and felt and of certain "first principles" upon which sound morality and religious beliefs could be established. Its basic principle was enunciated by its founder and greatest figure, Thomas Reid: If there are certain principles, as I think there are, which the constitution of our nature leads us to believe, and which we are under a necessity to take for granted in the common concerns of life, without being able to give a reason for them—these are what we call the principles of common sense; and what is manifestly contrary to them, is what we call absurd. Late modern philosophy In late modern philosophy, a notable school of thought advocating metaphysical realism was Austrian realism. Its members included Franz Brentano, Alexius Meinong, Vittorio Benussi, Ernst Mally, and early Edmund Husserl. These thinkers stressed the objectivity of truth and its independence of the nature of those who judge it. (See also Graz School.) Dialectical materialism, a philosophy of nature based on the writings of late modern philosophers Karl Marx and Friedrich Engels, is interpreted to be a form of ontological realism. According to Michael Resnik, Gottlob Frege's work after 1891 can be interpreted as a contribution to realism. Contemporary philosophy In contemporary analytic philosophy, Bertrand Russell, Ludwig Wittgenstein, J. L. Austin, Karl Popper, and Gustav Bergmann espoused metaphysical realism. Hilary Putnam initially espoused metaphysical realism, but he later embraced a form of anti-realism that he termed "internal realism." Conceptualist realism (a view put forward by David Wiggins) is a form of realism, according to which our conceptual framework maps reality. Speculative realism is a movement in contemporary Continental-inspired philosophy that defines itself loosely in its stance of metaphysical realism against the dominant forms of post-Kantian philosophy. See also Anti-realism Critical realism Dialectical realism Epistemological realism Extended modal realism Legal realism Modal realism Objectivism Philosophy of social science Principle of bivalence Problem of future contingents Realism (disambiguation) Truth-value link realism Speculative realism Direct and indirect realism Notes References External links Miller, Alexander, "Realism", The Stanford Encyclopedia of Philosophy (SEP) O'Brien, Daniel, "Objects of Perception", The Internet Encyclopedia of Philosophy (IEP) An experimental test of non-local realism. Physics research paper in Nature which gives negative experimental results for certain classes of realism in the sense of physics.