As theories are the means by which we attempt to discourse of external existences that our senses cannot discover; and as the desire for such discourse originates a large portion of our theories; I will teach you the capacity of language for such an employment, and thereby enable you to judge more understandingly than you can at present, the utility of most theories, and the signification of all.

Lecture I. §4. - A Treatise on Language: Or, The Relation which Words Bear to Things, in Four Parts (1836)