 latter. Though he made a great deal of the significance of his employment of the principle of association when giving summary presentations of his work, one of Condillac's great shortcomings is his treatment of association. He did little more than employ the term. Unlike Hume, he did not distinguish between resemblance, contiguity, and cause and effect, and he offered no detailed analysis of causal association. When compared with Hume's accounts of how association is responsible for our beliefs about matters of chance and probability, our trust in testimony, our reliance on general rules, and our tendencies to allow our reasoning to be influenced by credulity, education, and passion, Condillac's account of association is very impoverished.
Natural signs are the cries and gestures that we instinctively produce upon having particular experiences. Unlike Reid, Condillac insisted that we are not born with a knowledge of the meaning of natural signs; we are only born with the disposition to produce them on certain occasions. We produce them, moreover, without intending to do so and without intending to communicate anything by them. We only discover that they have a certain signification through hearing or seeing ourselves or others produce the sign on characteristic occasions, and so coming to associate the latter with the former. To go in the other direction, and produce the sign in order to induce the thought of some circumstance in others, would be to use the sign as an instituted rather than a natural sign.
The same might be said of accidental signs. To imagine dawn upon hearing the crow of a cock is to be affected by an accidental sign; to imitate the crow of a cock in order to signify dawn is to institute a sign, and is an operation of a higher order.
Reid was later to maintain that the creation of instituted signs presupposes an agreement among a community of speakers, which in turn presupposes language, and this led him to declare that there must be some language that is innately understood rather than established by convention. But Condillac had already explained how an artificial language can be instituted without innately understood signs (Essay II.i.1. §§1–4). Familiarity with the signification of natural signs, which are instinctively produced but not innately understood, will lead one to think of the sign upon witnessing the object that it signifies. For example, having learned to associate the cries that are made by those attacked by a wild animal with those circumstances, I will think of those cries upon seeing a wild animal approach and think of the effect that hearing them has previously had on myself and others. It is then a small, but momentous step to utter those cries in order, first, to signify the approach of a wild animal to others and induce them to flee, and then to signify this particular danger to oneself or others without bothering to imagine an approaching wild animal, as a way of abbreviating the process of thought. With this step, a move is made from being affected by accidental and natural signs we happen to chance upon in the course of experience to employing instituted signs to stand for experiences. The first stage in taking this step is the development of what Condillac called the “language of action,” a language composed of cries and gestures culled from natural language. A spoken language of arbitrary sounds and a written language are then gradually invented by users of the language of action (Essay II.i.1. §§5–8).
Since memory just is the imagination of signs, the development of instituted signs makes memory possible (natural and accidental signs are only ever sensed, not remembered). The institution of signs further allows us to set up names for groups of ideas that are too complicated to be distinctively yet collectively imagined, such as ideas of any number larger than six, of substances, of complex modes (notably moral and aesthetic qualities) and of genera and species of things (Essay I.iv). It is also supposed to give us control over our imagination and an ability to govern our 