Dialectical materialism

Dialectical materialism is a philosophy of science that serves as the philosophical basis of orthodox Marxism. Developed by communists—notably Vladimir Lenin—as an extension of the ideas of Karl Marx and Friedrich Engels, it applies the general Marxist idea of struggle between opposing forces to a broader context than the social "class struggle," emphasizing constant change (dialectics) and an objective physical existence (materialism). While dialectical materialism is associated with Marx and Engels, neither coined the term; Marx described his view of history as historical materialism. Dialectical materialism is influenced by Hegel's dialectics—a force in nature (or any other phenomena) comes into conflict with another force—the result being a synthesis of both, according to the original theory.

Dialectical materialism and science
When dialectical materialists like a branch of science, they'll blandly describe its current state, then append "Therefore, dialectics!" to it. When they don't, you can expect to see it branded bourgeois pseudoscience. The explanation of quantum wave nature is a quote by Engels that during motion, an object is at multiple places at once. The first problem in this is that everything in the Universe is moving, so every object must always be in wave number. The second problem is that that it makes zero sense.

Sometimes dialectical materialists like a branch of science but dislike actual scientists' approach to it. While dialectical materialists like quantum mechanics, they chide scientists for their apparent obsession with finding the smallest possible particles—because the dynamism required by dialectics means there can never be any fundamental particles, rather, science will continually find smaller and smaller sub-particles. (Also, they really like punctuated equilibrium — big dynamic events are apparently more dialectic than gradual change. )

As state ideology
When communists came to power in the Soviet Union and elsewhere, dialectical materialism was effectively made into a state religion in communist countries, and was developed extensively by philosophers in the Second World.

In the 1920s there was a philosophical debate in USSR about whether Marxist philosophy must follow science or vice-versa. The dialecticians emphasized that dialectics is fundamental to science. (And what is not dialectical is Pseudoscience.) Needless to say, Stalin chose dialectics officially in 1931. Independent philosophical debate was extinguished.

In the Soviet Union especially, all fields of science had to be policed to ensure conformity with what was called "dialectical materialism", and many fields were found wanting, including genetics, quantum mechanics, and sociology.

Some later thinkers, including Stephen Jay Gould, have attempted to distance themselves from Soviet-style dialectical materialism, advocating its use as a methodology but not an ideology.