Foremost William of Ockham developed the theory of mental language in the fourteenth century. 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 was caused efficiently by a thing in the world. It signifies that thing also because of the causal relation between them. The object and the concept are said to covary. On Ockham’s view, a mental representation or concept is caused by an intuitive cognition:
> Intuitive cognition is the proper cognition of a singular not because of its greater likeness to one thing more than another but because it is naturally caused by one thing and not by another; nor can it be caused by another. If you object that it can be caused by God alone, I reply that this is true: such a visual apprehension is always apt to be caused by one created object and not by another; and if it is caused naturally, it is caused by one thing and not by another, and it is not able to be caused by another. (Quodlibeta septem 1.13)
According to Ockham’s metaphysics there are only individuals in the world so that when an individual causes a concept to exist in the mind, it causes an individual concept and hence a singular conception of itself. Nothing else can cause that concept (except perhaps God). The singular concept functions as the word of the object that caused it in our language ofthought. It is an atomic constituent that can then be combined to form more complex concepts or sentences in the language. In this way, one can say that Ockham develops a kind of medieval functionalism, since the determinate content of a concept is fully specified by the input (covariance) and the output (linguistic role) (see King 2007).
Ockham’s notion of concept acquisition and mental representation is developed as part of a very sophisticated theory of thought involving not only a theory of signification, but also a whole range of logico-semantic properties such as connotation and supposition. It explains how concepts, which in turn are the direct objects of belief and knowledge, are assembled into mental sentences describing the world (for the details, see Panaccio 2004).
World History
