CHAP. II.] SIGNS AND THEIR LAWS. 25 



processes of thought the direct object of inquiry, we appeal in a 

 more immediate way to our personal consciousness, it will be 

 found that in both cases the results obtained are formally equi- 

 valent. Nor could we easily conceive, that the unnumbered 

 tongues and dialects of the earth should have preserved through 

 a long succession of ages so much that is common and universal, 

 were we not assured of the existence of some deep foundation of 

 their agreement in the laws of the mind itself. 



2. The elements of which all language consists are signs or 

 symbols. Words are signs. Sometimes they are said to repre- 

 sent things ; sometimes the operations by which the mind com- 

 bines together the simple notions of things into complex concep- 

 tions ; sometimes they express the relations of action, passion, or 

 mere quality, which we perceive to exist among the objects of our 

 experience ; sometimes the emotions of the perceiving mind. But 

 words, although in this and in other ways they fulfil the office of 

 signs, or representative symbols, are not the only signs which we 

 are capable of employing. Arbitrary marks, which speak only to 

 the eye, and arbitrary sounds or actions, which address themselves 

 to some other sense, are equally of the nature of signs, provided 

 that their representative office is defined and understood. In the 

 mathematical sciences, letters, and the symbols + , - , = , &c., are 

 used as signs, although the term " sign" is applied to the latter 

 class of symbols, which represent operations or relations, rather 

 than to the former, which represent the elements of number and 

 quantity. As the real import of a sign does not in any way de- 

 pend upon its particular form or expression, so neither do the 

 laws which determine its use. In the present treatise, however, 

 it is with written signs that we have to do, and it is with reference 

 to these exclusively that the term " sign" will be employed. The 

 essential properties of signs are enumerated in the following de- 

 finition. 



Definition. A sign is an arbitrary mark, having a fixed in- 

 terpretation, and susceptible of combination with other signs in 

 subjection to fixed laws dependent upon their mutual interpre- 

 tation. 



3. Let us consider the particulars involved in the above de- 

 finition separately. 



