 The theory of mental language in the fourteenth century was foremost developed by William Ockham. It rests on a theory of mental representation that combined the notions of cause and signification. A concept or a mental term on this view represents because it is caused efficiently by a thing in the world. It signifies that thing also because of the causal relation between them. On Ockham’s view, a mental representation or concept is caused by an intuitive cognition. He explains: