The theme was based on revolt against materialism, rationalism, positivism, bourgeois society and liberal democracy. The theme was based on a revolt against materialism, rationalism, positivism, bourgeois society and democracy. In contrast to positivism and idealism, CR combines a realist ontology with an interpretivist epistemology. It covers Logical positivism and Existentialism. Some authors have proposed that Bohr was influenced by positivism (or even pragmatism). This conception of a proposition was supported by the philosophical school of logical positivism. Ernst Mach's positivism and phenomenalism were a major influence. In essence Spencer's philosophical vision was formed by a combination of deism and positivism. Grounded theory combines diverse traditions in sociology, positivism and symbolic interactionism. Scientific realism is developed largely as a reaction to logical positivism. This means that legal realists oppose most versions of contemporary legal positivism. Placing realism under positivism is far from unproblematic however. One of the first thinkers to criticize logical positivism was Sir Karl Popper. These various thinkers were united by a distrust of Victorian positivism and certainty. This distinction was central to logical positivism.