The theory (coherent scientific explanation of an observable fact) that some diseases are caused by microorganisms.

plural of grand unification theory

The theory of the psychological process whereby deliberate attempts to suppress certain thoughts make them more likely to surface.

A speculative theory that human language originated from the imitation of animal vocalisations.

A speculative theory that human language originated from emotional exclamations of pain, pleasure, surprise, etc.

A speculative theory that human language originated from using tongue movements to mimic manual gestures.

(physics) A gauge theory that seeks to describe the behaviour of elementary particles using certain Lie groups. It is important in the unification of the electromagnetic force and weak nuclear force.

A movement in academia involving the application of critical theory to issues surrounding the interaction between racial dynamics and social and legal power.

(economics, political science) Alternative form of labor theory of value.

(economics, political science) Alternative form of labor theory of value.