398 OBSERVATIONS ON THE 



ry men, thinking of things, and thinking of the signs of things, 

 are peculiarly apt to be co-existent. This co-existence, gene- 

 rating confusion, has probably bhssed the estimate which me- 

 taphysicians have formed of the universal and necessary influ- 

 ence of language. 



It has been said in proof of the necessity of language even 

 to the act of thought itself, that there are many mental pro- 

 cesses which cannot be conducted without the intervention of 

 signs similar to those of language. Examples of this kind in 

 the mathematical sciences are considered as occurring in great 

 abundance. The signs in such examples become indeed pro- 

 minent and useful objects of thought to the student of science, 

 but they are perhaps in no greater degree the instruments of 

 thought than land-marks are the instruments of navigation, or 

 milestones the instruments of travelling. When we have com- 

 pleted a mathematical calculation, resulting in a precise and 

 comprehensive theorem, this result is expressed by a more or 

 less complicated sign. The sign in its various uses employs 

 our active thoughts ; but we have numerous thoughts about 

 this sign itself, for which we do not in our private meditations 

 use any signs. The leading sign, which we in this instance 

 employ, enables us to refer with facility to our past operations, 

 so as to secure precision in our further studies ; but such 

 thoughts as merely serve the purpose of the moment are not 

 even accompanied with the silent use of speech or of signs. 

 We may perhaps find the same fact illustrated in a different 

 way, by attending to the state of our thoughts, in so far as lan- 

 guage is concerned, when we exercise the understanding on a 

 moral subject. We shall probably be conscious that, when we 

 obtain a new idea, this often exists for some time in the mind 

 before we can find an appropriate expression for it, and, after 

 all, our best expressions are rather regarded as hints for elicit- 

 ing 



