remember to ourselves” (EW I.15; emphasis added). Therefore, he concludes, names are accurately defined in the manner expressed at De corpore 2.4 (EW I.16) – marks as instruments for thinking and, also, when expressed to others, signs for the communication of thought (EW I.15).
5.3 Truth and Propositional Judgments
Without the use of language an animal’s ability to make inferences, to navigate, know about, and manipulate the world, is exhausted by its power to make successful conjectures by signs. Though good enough for an animal’s daily needs, natural prudence is limited in two important respects, both of which Hobbes characterizes as problems with the memory (e.g., EW I.13–14; EW IV.20). First, as I have already pointed out, since conceptions are not general concepts, the mind cannot naturally form general representations – concept possession, without language, consists in an organism’s ability to project regularities, remembered and recalled as signs. In Leviathan (Hobbes 2012, 52; 1651, 13) and De corpore (EW I.80), Hobbes gives the example of a person doing geometry without using language to make the point. By observing figures in sensory experience – by drawing a diagram and visually inspecting it, perhaps – a person can come to recognize that the sum of the interior angles of a triangle equal two right angles. However, without a general representation of triangularity, “if another triangle be shewn him different in shape from the former, he cannot know without a new labour, whether the three angles of that also be equall to the same” (Hobbes 2012, 52; 1651, 4). Using only his natural cognitive powers his possession of the concept of triangle is limited to his ability to reliably conjecture, from his memories of particular triangles, that the next triangle he encounters will also have interior angles equivalent to two right angles; without the capacity to deploy general representations in cognition, he cannot permanently store the inferential sequence that led him to discover that the interior angles of a three-sided figure are equal to two right angles.
The second problem is that the decay of conceptions introduces errors into the natural process of inference. Since natural cognitive processes involve a “comparison” of ideas, as ideas lose their informational capacity, so they become less and less reliable when deployed in inferences. “Tacit errors, or errors of sense and cogitation” arise, therefore, in the transition from one mental representation to another in inferential processes (EW I.56–7). Hence, for example, without a “sensible measure” by which to preserve the fact that a given figure was so many units wide, it will not be possible for a person to reliably infer that some new figure she encounters has a width of the same number of units (EW I.13).
To overcome these limitations, human beings invent marks: “sensible things taken at pleasure, that, by the sense of them, such thoughts may be recalled to our mind as are like those thought for which we took them” (EW I.14; also EW IV.20). Marks are genuine symbols, in the sense that they are physical tokens, the meaning of which is fixed by conventions governing their use. The point of marks is not so much to help forgetful people remember things they would not otherwise have remembered (although marks can do this); rather, more generally marks help the mark-user raise conceptions in her mind to make inferences and to guide her behavior. The symbolic import of a mark is constituted by its function in cognition. The example Hobbes gives in Elements of Law of sailors who float a buoy to mark a submerged rock to “remember their former danger, and avoid it” (EW IV.20) illustrates the point. The sailors in Hobbes’s example recall that there is a potentially dangerous rock below the water’s surface; they just cannot see the rock from their boat, as they approach it. The buoy, as a mark, causes the sailor to think about the rock (i.e., to raise conceptions of the rock) and they can take appropriate action; that is the sense in which the buoy helps the sailors’ memory. The sailors introduce the device to help themselves recall the rock so that they can then make deliberations, take action, etc. The buoy thereby “points to” the submerged rock, because it causes a sequence of conceptions involving conceptions (memories) of the rock. What makes the buoy a mark is the functional role played by the buoy in cognition. By a standing convention – a rule governing its use – the causal role of the buoy is fixed and, as a mark, it is able to reliably convey information from one time to the next. To grasp the symbolic import of the buoy as a mark is to know the role of the buoy in cognition.
Hobbes does not say much about the relationship between marks and conventional signs beyond the comment in De corpore that “[t]he difference, therefore, betwixt marks and signs is this, that those we make for our own use, but these for the use of others” (EW I.15). I will return to this point below, when I discuss the relationship between names in their role as marks and names as signs of thought, but here I point out the following. First, although Hobbes does not explicitly walk his readers through the process, I think it is reasonably easy to see how a mark, invented for the sake of private cognition, can become a sign to other people of what it marks. Take one of Hobbes’s examples of an artificial sign – stones set in a field to mark the boundary of the field. One can imagine a case in which a farmer, having trouble recalling the exact extent of his field (without “present and sensible measures”), hits upon the idea of putting stones in the ground to mark the boundary. A stone’s function as a mark is to cause the farmer to think about the boundary of his field; once his neighbor knows that this is how the farmer uses these stones, the stones become a sign to his neighbor of the same, causing him to think about the boundary of the field. It is not hard to imagine the community adopting this method – setting stones into the ground – to mark the boundaries of their fields and, also, to signify to their neighbors what they take to be that boundary. It is also easy to imagine this mark-to-sign process happening without explicit teaching. By observing the sailors’ behavior, for example, it would become clear what they are using the buoy for. In both cases, experience could “train someone to see” the mark as a sign, that is, to develop the right cognitive disposition.
Second, a “sensible moniment” is a mark when it is used in private cognition, but a sign where there is common knowledge of its function as a mark; this common knowledge, however, is not essential to the symbolic import of a mark. That is constituted by its role in individual cognition (EW I.14–15).
Names are distinguished from other “human voices” and from other sorts of marks by their specific role in cognition. Names are constituted by the role they play in the act of reasoning. They are imposed on objects, for the sake of recalling conceptions of those objects. Strung together into grammatical sentences, names “register” and “record” the consequences of thoughts through their imposition and their concatenation in the act of reasoning.
“Imposition” is a technical term, which, like “signification,” is borrowed from Scholastic semiotic theory. Hobbesian names function as categorematic terms and not singular terms. To “impose” a name is to establish a convention that fixes the extension of the name. Names “appellate” what they are “imposed on” or that of which they are truly predicable.5 A common name, “as Man, Horse, Tree, [is] the name of divers particular things; in respect of all which together, it is called an Universall” (Hobbes 2012, 52; 1651, 13). Proper names, “singular to one onely thing,” (Hobbes 2012, 52; 1651, 13) are a limiting case. They are also categorematic terms, imposed upon objects for the sake of recalling conceptions of those object, but which apply to exactly one thing as “he that writ the Illiad” (EW I.19) is imposed upon Homer to register the thought that he authored the Illiad or “Appius” and “Lentulus” apply to Appius and Lentulus for “(as Cicero has it) Appiety and Lentulity” (EW I.32). Imposition marks out a class – the class of objects, unified by the fact that each individual member of the class causes a similar suite of sensory appearances in the human organism. As I pointed out above, Hobbes is clear that, prior to the use of language, animals are capable of making perceptual discriminations, selectively attending to features of individual objects, recognizing similarities between individual objects, and remembering these, albeit imperfectly. A name is imposed upon many distinct individuals that resemble one another with respect to some feature. There are no universal properties ex parte rem nor universal mental representations, according to Hobbes’s austere nominalism. Class membership is analyzed in terms of the brute resemblance each